METHOD FOR DETERMINATION OF DOUBLE-STRANDED RNA IMPURITY

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application Nos. 63/376,544, filed on September 21, 2022, the disclosures of each which are incorporated by reference herein in its entirety for all purposes.

BACKGROUND

[0002] The development of in vitro messenger RNA (mRNA) platform technology for expressing therapeutic proteins has gained a lot of focus for treatment of several diseases. Large scale manufacturing of mRNA is typically contaminated by double stranded RNA (dsRNA), which is a by-product of in vitro transcription. The dsRNA contamination is particularly problematic due to induction of immunogenic reaction in patients. The dsRNA can be recognized by endosomal innate immune receptors (TLR-3) and cytoplasmic innate immune receptors (PKR, RIG-I, MDA5 and OAS), stimulating the secretion of pro-inflammatory cytokines and type I interferon (IFN), leading to the activation of antigen-presenting cells (APCs) and the generation of inflammatory responses. The dsRNA can also activate antiviral enzymes, resulting in stalled mRNA translation and mRNA degradation.

[0003] Current methods for assessing dsRNA impurity using immune-dot blot or immunoblotting have significant limitations. For example, quantitation of dsRNA using immunoblotting based on chemiluminescence image analysis suffers from inconsistency depending on blot background and high run-to-run variability and is technically difficult to execute and not QC-friendly. As such, there is a need for quantitative and robust analytical methods for detection of dsRNA in therapeutic mRNA preparations. The present disclosure provides a novel enzyme-linked immunosorbent assay (ELISA) based method and buffer compositions for use with the disclosed ELISA method, for generating a linear standard curve and detection of dsRNA contamination in therapeutic mRNA preparations that can facilitate determination of the quality of the mRNA preparation in terms of immunogenic potential. SUMMARY

[0004] Disclosed herein is a method of quantitatively measuring an amount of double-stranded RNA (dsRNA) present in a sample solution, the method comprising: a) contacting the sample solution with a dsRNA capture reagent and a dsRNA detection reagent, and detecting a signal from the dsRNA detection reagent in the sample solution; b) calculating a dsRNA detection reagent signal using the signal from the dsRNA detection reagent in the sample solution; c) contacting dilutions of a dsRNA standard solution with a dsRNA capture reagent and a dsRNA detection reagent, and detecting a signal from the dsRNA detection reagent in each dilution of the dsRNA standard solution; d) generating a calibration curve using the signal from the dsRNA detection reagent at each dilution of the dsRNA standard solution; and e) comparing the dsRNA detection reagent signal with the calibration curve to quantitatively determine the concentration of dsRNA in the sample solution; wherein the dsRNA standard solution comprises a molecular crowding agent; and the dilutions of the dsRNA standard solution comprise from about 0.0001 pg/ml dsRNA to about 5 pg/ml dsRNA.

[0005] Also provided herein is a composition for use as a dsRNA standard solution, the composition comprising dsRNA polynucleotides of one or more defined lengths in base pairs (bp) and a molecular crowding agent.

[0006] Also provided herein is a kit for quantitative measurement of dsRNA present in a sample solution, the kit comprising: a dsRNA standard solution comprising dsRNA polynucleotides and a molecular crowding agent; and one or more reagents for carrying out an assay for detecting dsRNA present in a sample solution.

[0007] Also provided herein is a method of screening a set of procedures for reducing dsRNA content of a sample solution comprising a known amount of dsRNA, the method comprising: performing each of the set of procedures on an amount of the sample solution for an amount of time to form a set of test sample solutions, the amount of sample solution and amount of time being same for each compound of the set; and quantifying the amount of dsRNA in each test sample solution using the method of the present disclosure; and determining if a procedure of the set is effective in reducing dsRNA from the sample if the concentration of dsRNA in the corresponding test sample solution is reduced by at least 90%, as compared to the sample solution before contacting with the compound. [0008] Also provided herein, a method of correlating an amount of dsRNA in a sample solution with immunogenicity of the sample solution, the method comprising: quantitatively measuring the amount of dsRNA present in the sample solution using the method of the present disclosure; quantitatively measuring the level an immune activation signal induced by the sample by conducting an in vitro immune activation assay using the sample; and determining the amount of dsRNA to be non-immunogenic if the level of immune receptor activation induced by the sample as determined in (b) is less than or equal to a pre-determined value.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIGs. 1 A-1B depict outlines of the processes and set up of the ELISA based method for detecting dsRNA in samples, as described herein. FIG. 1 A is a flow chart describing the key steps of the ELISA based method for detecting dsRNA in samples, as described herein. FIG. IB depicts a plate layout for conducting an ELISA platform based method of the present disclosure. Each serial dilution of the standard (wells Al-Al 1, Bl-Bl 1, and Cl-Cl 1) reference standard (RS, wells D1-D3, E1-E3 and F1-F3) and samples (SI, wells D4-D6, E4-E6 and F4-F6; S2, wells D7-D9, E7-E9 and F7-F9; S3, wells D10-D12, E10-E12 and F10-F12, S4, wells G1-G3, H1-H3, and G4- G6, S5, wells G7-G9, H7-H9 and G10-G12) were plated in triplicates, as indicated.

[0010] FIG. 2 depicts a standard curve generated by plotting the concentration of dsRNA in serial dilutions of a standard dsRNA solution (y-axis) against the colorimetric signal read at an absorbance rate of 450 nm (axis) as determined by using the ELISA platform based method of the present disclosure, using a J2 capture antibody and a K2 detection antibody and PEG-8000 crowing agent. The linear equation and linear regression coefficient of the standard curve are as indicated. [0011] FIGs. 3A-3B depict comparison of the performance of an ELISA platform based method of the present disclosure with immunoblotting method (Dot Blot assay) for determining dsRNA level in sample. FIG. 3A is a chart showing a comparison of different parameters, as indicated, between the ELISA platform and Dot Blot assay. Representative results used for the parameter comparisons are also provided. FIG. 3B is a chart depicting dilution linearity and repeatability of the ELISA platform based method of the present disclosure. FIG. 3C depicts histogram plot comparing relative level of dsRNA (bar graph) determined using the Dot Blot assay and ELISA platform based method of the present disclosure.

[0012] FIGs. 4A-4C depict design and performance of an assay for correlating the level of dsRNA quantified using the ELISA platform based method of the present disclosure. FIG. 4A is a diagram depicting an in vitro immune activation assay using a HEK -Lucia RIG-I cell for detecting immune activation induced by dsRNA in a sample. The HEK -Lucia RIG-I cell comprises a luciferase reporter gene (Lucia) operatively linked to an interferon stimulation response element (ISRE) and a portion of interferon stimulated gene 4 (ISG4), wherein the activation of the RIG-I pathway by dsRNA leads to activation of Lucia reporter gene and generation of a detectable signal, as indicated. FIG. 4B depicts histogram plot overlay comparing the level of RIG-I response detected in HEK -Lucia RIG-I cell based assay (line graph), with the relative level of dsRNA (bar graph) determined using the ELISA platform based method of the present disclosure (y-axis), in samples containing different proportions of low and high dsRNA, as indicated on x-axis. FIG. 4C depicts histogram plot overlay comparing the level of RIG-I response detected in HEK -Lucia RIG- I cell based assay (line graph), with the relative level of dsRNA (bar graph) determined using the ELISA platform based method of the present disclosure (y-axis), in different samples, as indicated on x-axis.

[0013] FIG. 5. depicts a standard curve generated by plotting the concentration of dsRNA in serial dilutions of a standard dsRNA solution (y-axis) against the colorimetric signal read at an absorbance rate of 450 nm (axis) as determined by using the ELISA platform based method of the present disclosure, using a K2 capture antibody and a KI detection antibody and Ficoll® crowding agent. The linear equation and linear regression coefficient of the standard curve are as indicated.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

[0014] The present disclosure provides improved enzyme linked immunosorbent assay (ELISA) based methods and compositions for use in the disclosed methods, for detecting dsRNA in, e.g., compositions containing therapeutic mRNA.

[0015] In one aspect, the present disclosure provides a method of quantitatively measuring an amount of double-stranded RNA (dsRNA) present in a sample solution, the method comprising: a) contacting the sample solution with a dsRNA capture reagent and a dsRNA detection reagent, and detecting a signal from the dsRNA detection reagent in the sample solution; b) calculating a dsRNA detection reagent signal using the signal from the dsRNA detection reagent in the sample solution; c) contacting dilutions of a dsRNA standard solution with a dsRNA capture reagent and a dsRNA detection reagent, and detecting a signal from the dsRNA detection reagent in each dilution of the dsRNA standard solution; d) generating a calibration curve using the signal from the dsRNA detection reagent at each dilution of the dsRNA standard solution; and e) comparing the dsRNA detection reagent signal with the calibration curve to quantitatively determine the concentration of dsRNA in the sample solution; wherein the dsRNA standard solution comprises a molecular crowding agent; and the dilutions of the dsRNA standard solution comprise from about 0.0001 pg/ml dsRNA to about 5 pg/ml dsRNA.

[0016] In some embodiments, the molecular crowding agent comprises a double- stranded conformation-stabilizing polymer. In some embodiments, the molecular crowding agent comprises a polyethylene glycol (PEG), a dextran, or a Ficoll®. In some embodiments, the molecular crowding agent is present at a concentration effective to stabilize a double-stranded conformation of the dsRNA polynucleotides.

[0017] In some embodiments, the molecular crowding agent is PEG-400, PEG-800, PEG-1500, PEG-3000, PEG-6000, or PEG-8000 (collectively, “PEG”). In some embodiments, the PEG is present in the dsRNA standard solution at a concentration of about 0.01% v/v to about 50% v/v (e.g., about 0.01% v/v to about 0.05% v/v, about 0.05% v/v to about 0.1% v/v, about 0.1% v/v to about 0.5% v/v, about 0.5% v/v to about 1% v/v, about 1% v/v to about 5% v/v, about 5% v/v to about 10% v/v, about 10% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, about 25% v/v to about 30% v/v, about 30% v/v to about 35% v/v, about 35% v/v to about 40% v/v, about 40% v/v to about 45% v/v, about 45% v/v to about 50% v/v, about 0.01% v/v to about 45% v/v, about 0.05% v/v to about 50% v/v, about 0.1% v/v to about 40% v/v, about 0.5% v/v to about 35% v/v, about 1% v/v to about 30% v/v, about 5% v/v to about 25% v/v, about 10% v/v to about 20% v/v, about 10% v/v to about 15% v/v or about 15% v/v to about 20% v/v, and all percentages including and in between about 0.01% v/v to about 50% v/v) before dilution.

[0018] In some embodiments, the molecular crowding agent is PEG-8000. In some embodiments, the PEG-8000 is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 15% v/v (e.g., about 0.1% v/v to about 0.25% v/v, about 0.25% v/v to about 0.5% v/v, about 0.5% v/v to about 0.75% v/v, about 0.75% v/v to about 1% v/v, about 1% v/v to about 1.5% v/v, about 1.5% v/v to about 2% v/v, about 2% v/v to about 2.5% v/v, about 2.5% v/v to about 5% v/v, about 5% v/v to about 7.5% v/v, about 7.5% v/v to about 10% v/v, about 10% v/v to about 12.5% v/v, about 12.5% v/v to about 15% v/v, about 0.1% v/v to about 10% v/v, about 0.25% v/v to about 15% v/v, about 0.5% v/v to about 12.5% v/v, about 0.75% v/v to about 10% v/v, about 1% v/v to about 7.5% v/v, about 1.5% v/v to about 5% v/v, about 2% v/v to about 5% v/v, about 1% v/v to about 2.5% v/v, about 1.5% v/v to about 2.5% v/v and all percentages including and in between about 0.1% v/v to about 15% v/v) before dilution.

[0019] In some embodiments, the molecular crowding agent is a dextran. In some embodiments, the molecular crowding agent is a dextran-40 or dextran-70. In some embodiments, the dextran is present in the dsRNA standard solution at a concentration of about 0.01% v/v to about 50% v/v (e.g., about 0.01% v/v to about 0.05% v/v, about 0.05% v/v to about 0.1% v/v, about 0.1 % v/v to about 0.5% v/v, about 0.5% v/v to about 1 % v/v, about 1 % v/v to about 5% v/v, about 5% v/v to about 10% v/v, about 10% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, about 25% v/v to about 30% v/v, about 30% v/v to about 35% v/v, about 35% v/v to about 40% v/v, about 40% v/v to about 45% v/v, about 45% v/v to about 50% v/v, about 0.01% v/v to about 45% v/v, about 0.05% v/v to about 50% v/v, about 0.1% v/v to about 40% v/v, about 0.5% v/v to about 35% v/v, about 1% v/v to about 30% v/v, about 5% v/v to about 25% v/v, about 10% v/v to about 20% v/v, about 10% v/v to about 15% v/v or about 15% v/v to about 20% v/v, and all percentages including and in between about 0.01% v/v to about 50% v/v and all percentages including and in between about 0.01% v/v to about 50% v/v) before dilution.

[0020] In some embodiments, the dilutions of the dsRNA standard solution comprise the dextran at a concentration of about 0.1% v/v to about 25% v/v (e g., about 0.1% v/v to about 0.25% v/v, about 0.25% v/v to about 0.5% v/v, about 0.5% v/v to about 0.75% v/v, about 0.75% v/v to about 1% v/v, about 1% v/v to about 1.5% v/v, about 1.5% v/v to about 2% v/v, about 2% v/v to about 2.5% v/v, about 2.5% v/v to about 5% v/v, about 5% v/v to about 7.5% v/v, about 7.5% v/v to about 10% v/v, about 10% v/v to about 12.5% v/v, about 12.5% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, or about 0.1% v/v to about 20% v/v, about 0.25% v/v to about 25% v/v, about 0.5% v/v to about 15% v/v, about 0.75% v/v to about 12.5% v/v, about 1% v/v to about 10% v/v, about 1.5% v/v to about 7.5% v/v, about 2% v/v to about 5% v/v, about 2.5% v/v to about 7.5% v/v, about 1.5% v/v to about 2.5% v/v and all percentages including and in between about 0.1% v/v to about 25% v/v) before dilution,

[0021] In some embodiments, the molecular crowding agent is a Ficoll®. In some embodiments, the molecular crowding agent is a Ficoll-Paque®, Ficoll-Paque®PLUS, Ficoll-Paque®Premium, and Ficoll®400. In some embodiments, the Ficoll® is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 50% v/v (e.g., about 0.1% v/v to about 0.25% v/v, about 0.25% v/v to about 0.5% v/v, about 0.5% v/v to about 0.75% v/v, about 0.75% v/v to about 1% v/v, about 1% v/v to about 1.5% v/v, about 1.5% v/v to about 2% v/v, about 2% v/v to about 2.5% v/v, about 2.5% v/v to about 5% v/v, about 5% v/v to about 7.5% v/v, about 7.5% v/v to about 10% v/v, about 10% v/v to about 12.5% v/v, about 12.5% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, about 25% v/v to about 30% v/v, about 30% v/v to about 35% v/v, about 35% v/v to about 40% v/v, about 40% v/v to about 45% v/v, about 45% v/v to about 50% v/v, about 0.1% v/v to about 45% v/v, about 0.25% v/v to about 50% v/v, about 0.5% v/v to about 40% v/v, about 0.75% v/v to about 35% v/v, about 1% v/v to about 30% v/v, about 1.5% v/v to about 25% v/v, about 2% v/v to about 20% v/v, about 2.5% v/v to about 15% v/v, about 5% v/v to about 12.5% v/v, about 7.5% v/v to about 12.5% v/v, about 5% v/v to about 10% v/v and all percentages including and in between about 0.1% v/v to about 50% v/v) before dilution before dilution.

[0022] In some embodiments, the method comprises an enzyme linked immunosorbent assay (ELISA) assay. In some embodiments, the method comprises any one of a sandwich ELISA assay and a direct ELISA. In some embodiments, the method comprises a sandwich ELISA assay.

[0023] In some embodiments, the dsRNA capture reagent is immobilized on a solid substrate. In some embodiments, the solid substrate is any one of polystyrene, polyethylene, polyacrylamide, agarose, glass, or silicone rubber. In some embodiments, the solid substrate is polystyrene. In some embodiments, the dsRNA capture reagent is immobilized on a microtiter plate, and in particular the preferred solid phase used is a multi-well microtiter plate that can be used to analyze several samples at one time, e.g., a microtest 96-well ELISA plate such as that sold as Nunc Maxisorp or Immulon. In certain embodiments, the plate is a MICROTEST™ or MAXISORP™ 96-well ELISA plate such as that sold as NUNC MAXISORP™ or IMMULON™.

[0024] In some embodiments, the dsRNA capture reagent is an antibody or fragment thereof that specifically binds dsRNA. In some embodiments, the capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of J2 (Schonborn et al., 1991), K2 (Schonborn et al., 1991), 9D5 (Kitagawa et al. 1977) or KI (Schonborn et al., 1991) antibody or a fragment thereof. In some embodiments, the capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of J2 or K2 antibody or a fragment thereof. In some embodiments, the capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as J2 antibody or a fragment thereof. In some embodiments, the capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as K2 antibody or a fragment thereof.

[0025] In some embodiments, the capture reagent is any one of J2, K2, 9D5 or KI antibody. In some embodiments, the capture reagent is any one of J2 or K2 antibody or a fragment thereof. In some embodiments, the capture reagent is a J2 antibody. In some embodiments, the capture reagent is a K2 antibody or a fragment thereof.

[0026] In some embodiments, the detection reagent is an antibody or fragment thereof. In some embodiments, the detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2, 12, 9D5 or KI antibody or a fragment thereof. In some embodiments, the detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2 or J2 antibody or a fragment thereof. In some embodiments, the detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as K2 antibody or a fragment thereof. In some embodiments, the detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as J2 antibody or a fragment thereof.

[0027] In some embodiments, the dsRNA capture reagent is an antibody or fragment thereof bound to Protein A immobilized on the solid substrate. In some embodiments, the dsRNA capture reagent is any one of an antibody or fragment thereof bound to Protein A immobilized on the solid substrate.

[0028] In some embodiments, the detection reagent is any one of J2, K2, 9D5 or KI antibody. In some embodiments, the detection reagent is any one of J2 or K2 antibody. In some embodiments, the detection reagent is a J2 antibody. In some embodiments, the detection reagent is a K2 antibody.

[0029] In some embodiments, the dsRNA capture reagent is an antibody or fragment thereof bound the solid substrate. In some embodiments, the dsRNA capture reagent is an antibody or fragment thereof bound to any one of Protein A, Protein G or Protein L or a combination thereof, immobilized on the solid substrate. In some embodiments, the dsRNA capture reagent is an antibody or fragment thereof bound to Protein A immobilized on the solid substrate. In some embodiments, the dsRNA capture reagent is any one of J2, K2, 9D5 or KI antibody or a fragment thereof, bound to any one of Protein A, Protein G or Protein L or a combination thereof, immobilized on the solid substrate. In some embodiments, the dsRNA capture reagent is any one of J2, K2, 9D5 or KI antibody or a fragment thereof, bound to any one of Protein A immobilized on the solid substrate. In some embodiments, the dsRNA capture reagent is any one of J2 antibody or a fragment thereof, bound to any one of Protein A immobilized on the solid substrate. In some embodiments, the dsRNA capture reagent is any one of K2 antibody or a fragment thereof, bound to any one of Protein A immobilized on the solid substrate.

[0030] In some embodiments, the concentration of the dsRNA capture reagent is about 0.1 pg/ml to about 1.0 pg/ml (e.g., about 0.1 pg/ml to 0.2 pg/ml, about 0.2 pg/ml to 0.3 pg/ml, about 0.3 pg/ml to 0.4 pg/ml, about 0.4 pg/ml to 0.5 pg/ml, about 0.5 pg/ml to 0.6 pg/ml, about 0.6 pg/ml to 0.7 pg/ml, about 0.7 pg/ml to 0.8 pg/ml, about 0.8 pg/ml to 0.9 pg/ml, about 0.9 pg/ml to 1 pg/ml, about 0.1 pg/ml to 0.9 pg/ml, about 0.2 pg/ml to 1 pg/ml, about 0.1 pg/ml to 0.9 pg/ml, about 0.2 pg/ml to 0.8 pg/ml or about 0.3 pg/ml to 0.7 pg/ml, about 0.4 pg/ml to 0.6 pg/ml, about 0.5 pg/ml to 0.7 pg/ml and all integers including and in between about 0.1 pg/ml to about 1.0 pg/ml and all integers including and in between about 0.1 pg/ml to about 1.0 pg/ml). In some embodiments, the concentration of the dsRNA capture reagent is about 0.5 pg/ml. In some embodiments, the concentration of the dsRNA capture reagent is 0.5 pg/ml.

[0031] In some embodiments, the dsRNA capture reagent is KI antibody or fragment thereof, and the dsRNA detection reagent is K2 antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is K I antibody or fragment thereof, and the dsRNA detection reagent is J2 antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is KI antibody or fragment thereof, and the dsRNA detection reagent is 9D5 antibody or fragment thereof.

[0032] In some embodiments, the dsRNA capture reagent is K2 antibody or fragment thereof, and the dsRNA detection reagent is KI antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is K2 antibody or fragment thereof, and the dsRNA detection reagent is J2 antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is K2 antibody or fragment thereof, and the dsRNA detection reagent is 9D5 antibody or fragment thereof.

[0033] In some embodiments, the dsRNA capture reagent is J2 antibody or fragment thereof, and the dsRNA detection reagent is KI antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is J2 antibody or fragment thereof, and the dsRNA detection reagent is K2 antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is J2 antibody or fragment thereof, and the dsRNA detection reagent is 9D5 antibody or fragment thereof.

[0034] In some embodiments, the dsRNA capture reagent is 9D5 antibody or fragment thereof, and the dsRNA detection reagent is KI antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is 9D5 antibody or fragment thereof, and the dsRNA detection reagent is K2 antibody or fragment thereof. In some embodiments, the dsRNA capture reagent is 9D5 antibody or fragment thereof, and the dsRNA detection reagent is J2 antibody or fragment thereof.

[0035] In some embodiments, the dsRNA detection reagent is an antibody or fragment thereof that specifically binds dsRNA and does not specifically bind Protein A, Protein G or Protein L or a combination thereof. In some embodiments, the dsRNA detection reagent is an antibody or fragment thereof that specifically binds dsRNA and does not specifically bind Protein A. In some embodiments, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2, J2, 9D5, or KI antibody or a fragment thereof. In some embodiments, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2 or J2 antibody or a fragment thereof. In some embodiments, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as K2 antibody or a fragment thereof. In some embodiments, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as J2 antibody or a fragment thereof.

[0036] In some embodiments, the dsRNA detection reagent is an IgM isotype antibody or fragment thereof that specifically binds dsRNA and does not specifically bind Protein A. In some embodiments, the dsRNA detection reagent is K2 IgM isotype antibody or antigen-binding fragment thereof.

[0037] In some embodiments, the dsRNA detection reagent is used at a dilution of about 1 :20 to about 1 : 100 (e.g., about 1 :20 to about 1:30, about 1 :30 to about 1:40, about 1 :40 to about 1 :50, about 1 :50 to about 1 :60, about 1 :60 to about 1 :70, about 1 :70 to about 1 :80, about 1 :80 to about 1 :90, about 1:90 to about 1 : 100, about 1 :20 to about 1 :90, about 1 :30 to about 1 : 100, about 1 :30 to about 1 :90, about 1 :40 to about 1 :80, about 1:50 to about 1 :70, about 1 :40 to about 1 :60, about 1 :30 to about 1 :50 and all ratios including and in between about 1 :20 to about 1 : 100). In some embodiments, the dsRNA detection reagent is used at a dilution of about 1 : 100.

[0038] In some embodiments, the dsRNA detection reagent is used at a concentration of about 0.05 pg/ml to about 10 pg/ml (e.g., about 0.05 pg/ml to about 0.1 pg/ml, about 0.1 pg/ l to about 0.5 pg/ml, about 0.5 pg/ml to about 1 pg/ml, about 1 pg/ml to about 2 pg/ml, about 2 pg/ml to about 5 pg/ml, about 5 pg/ l to about 10 pg/ml, about 0.05 pg/ l to about 5 pg/ml, about 0.1 pg/ml to about 1 pg/ml, about 0.5 pg/ml to about 2 pg/ml, about 0.05 pg/ml to about 2 pg/ml, and all concentrations including and in between about 0.05 pg/ml to about 10 pg/ml). In some embodiments, the dsRNA detection reagent is used at a concentration of about 0.05 pg/ml to about 10 pg/ml.

[0039] In some embodiments, the contacting of the sample and/or the standard solution with the dsRNA capture reagent and/or the dsRNA detection reagent, is carried out in a saline buffer comprising one or more coating agents or blocking agents. In some embodiments, the one or more coating agents or blocking agents is selected from gelatin, bovine serum albumin, egg albumin, casein, or non-fat milk. The blocking treatment typically takes place under conditions of ambient temperatures for about 1-4 hours, preferably about 1 to 3 hours, or overnight at 0-4° C. In some embodiments, the contacting of the sample and/or the standard solution with the dsRNA capture reagent and/or the dsRNA detection reagent, is carried out in IX phosphate buffer saline comprising bovine serum albumin (BSA).

[0040] In some embodiments, detecting a signal from the dsRNA detection reagent comprises contacting the detection reagent with a secondary detection reagent. In some embodiments, the secondary detection reagent is an antibody or fragment thereof that specifically binds the dsRNA detection reagent. In some embodiments, the secondary detection reagent comprises a reporter moiety. In some embodiments, the reporter moiety is a chromogenic enzyme. In some embodiments, the chromogenic enzyme is a horse-radish peroxidase (HRP), an alkaline phosphatase (AP), a 0-a galactosidase, an acetylcholinesterase, or a catalase. In some embodiments, the chromogenic enzyme is an HRP or an AP. In some embodiments, the chromogenic enzyme is an HRP. [0041] In some embodiments, the secondary detection reagent is an HRP-conjugated antimouse g-chain F(ab’)2 fragment. In some embodiments, the secondary detection reagent is an AP- conjugated anti-mouse g-chain F(ab’)2 fragment.

[0042] In some embodiments, the dsRNA standard solution comprises dsRNA polynucleotides of one or more defined lengths in base pairs (bp). In some embodiments, the dsRNA polynucleotides comprise one or more defined lengths of about 50 bp to about 10,000 bp (about 50 bp to about 100 bp, about 100 bp to about 250 bp, about 250 bp to about 500 bp, about 500 bp to about 750 bp, about 750 bp to about 1000 bp, about 1000 bp to about 2000 bp, about 2000 bp to about 3000 bp, about 3000 bp to about 4000 bp, about 4000 bp to about 5000 bp, about 5000 bp to about 6000 bp, about 6000 bp to about 7000 bp, about 7000 bp to about 8000 bp, about 8000 bp to about 9000 bp, about 9000 bp to about 10,000 bp, about 50 bp to about 9000 bp, about 100 bp to about 10,000 bp, about 100 bp to about 9000 bp, about 100 bp to about 8000 bp, about 250 bp to about 7000 bp, about 500 bp to about 6000 bp, about 750 bp to about 5,000 bp, about 1000 bp to about 4,000 bp, about 2000 bp to about 4,000 bp, about 250 bp to about 1000 bp, about 100 bp to about 250 bp, and all integers including and in between about 50 bp to about 10,000 bp.

[0043] In some embodiments, the one or more defined lengths of the dsRNA polynucleotides are in increments of about 5 bp, increments of about 10 bp, increments of about 20 bp, increments of about 50 bp, increments of about 100 bp, and/or increments of about 1,000 bp. In some embodiments, the dsRNA polynucleotides are of one or more defined lengths selected from one or more of about 50 bp, about 60 bp, about 70 bp, about 80 bp, about 90 bp, about 100 bp, about 150 bp, about 200 bp, about 250 bp, about 300 bp, about 350 bp, about 400 bp, about 450 bp, about 500 bp, about 550 bp, about 600 bp, about 650 bp, about 700 bp, about 750 bp, about 800 bp, about 850 bp, about 900 bp, about 950 bp, about 1,000 bp, about 1,100 bp, about 1,200 bp, about 1,300 bp, about 1,400 bp, about 1,500 bp, about 1,600 bp, about 1,700 bp, about 1,800 bp, about 1,900 bp, about 2,000 bp, about 2,100 bp, about 2,200 bp, about 2,300 bp, about 2400 bp, about 2,500 bp, about 2,600 bp, about 2,700 bp, about 2,800 bp, about 2,900 bp, about 3,000 bp, about 3,100 bp, about 3,200 bp, about 3,300 bp, about 3,400 bp, about 3,500 bp, about 3,600 bp, about 3,700 bp, about 3,800 bp, about 3,900 bp, about 4,000 bp, about 41,00 bp, about 4,200 bp, about 4,300 bp, about 4,400 bp, about 4,500 bp, about 4,600 bp, about 4,700 bp, about 4,800 bp, about 4,900 bp, about 5,000 bp, about 5,100 bp, about 5,200 bp, about 5,300 bp, about 5,400 bp, about 5,500 bp, about 5,600 bp, about 5,700 bp, about 5,800 bp, about 5,900 bp, about 6,000 bp, about 6,100 bp, about 6,200 bp, about 6,300 bp, about 6,400 bp, about 6,500 bp, about 6,600 bp, about 6,700 bp, about 6,800 bp, about 6,900 bp, about 7,000 bp, about 7,100 bp, about 7,200 bp, about 7,300 bp, about 7,400 bp, about 7,500 bp, about 7,600 bp, about 7,700 bp, about 7,800 bp, about 7,900 bp, about 8,000 bp, about 8,100 bp, about 8,200 bp, about 8,300 bp, about 8,400 bp, about 8,500 bp, about 8,600 bp, about 8,700 bp, about 8,800 bp, about 8,900 bp, about 9,000 bp, about 9,100 bp, about 9,200 bp, about 9,300 bp, about 9,400 bp, about 9,500 bp, about 9,600 bp, about 9,700 bp, about 9,800 bp, about 9,900 bp, and about 10,000 bp.

[0044] In some embodiments, the dsRNA polynucleotides are of one or more defined lengths of about 10 bp to about 1000 bp (e.g., about 10 bp to about 25 bp, about 25 bp to about 50 bp, about 50 bp to about 100 bp, about 100 bp to about 150 bp, about 150 bp to about 200 bp, about 200 bp to about 300 bp, about 300 bp to about 400 bp, about 400 bp to about 500 bp, about 500 bp to about 600 bp, about 600 bp to about 700 bp, about 700 bp to about 800 bp, about 800 bp to about 900 bp, about 900 bp to about 1000 bp, about 10 bp to about 900 bp, about 25 bp to about 900 bp, about 25 bp to about 800 bp, about 50 bp to about 700 bp, about 100 bp to about 600 bp, about 150 bp to about 500 bp, about 200 bp to about 400 bp, about 100 bp to about 300 bp, about 300 bp to about 500 bp and all integers including and in between about 10 bp to about 1000 bp).

[0045] In some embodiments, the dsRNA polynucleotides are of one or more defined lengths of about 100 bp to about 500 bp (e.g., about 100 bp to about 200 bp, about 200 bp to about 300 bp, about 300 bp to about 400 bp, about 400 bp to about 500 bp, about 100 bp to about 400 bp, about 200 bp to about 500 bp, about 100 bp to about 300 bp, about 200 bp to about 400 bp or about 300 bp to about 500 bp and all integers including and in between about 100 bp to about 500 bp).

[0046] In some embodiments, the dsRNA polynucleotides are of one or more defined lengths of about 200 bp to about 400 bp (e.g., about 200 bp to about 250 bp, about 200 bp to about 250 bp, about 250 bp to about 300 bp, about 300 bp to about 350 bp, about 350 bp to about 400 bp, about 200 bp to about 350 bp, about 250 bp to about 400 bp, about 250 bp to about 350 bp, about 300 bp to about 400 bp, about 200 bp to about 300 bp, about 300 bp to about 400 bp, about 400 bp to about 500 bp or about 250 bp to about 350 bp, and all integers including and in between about 200 bp to about 400 bp). In some embodiments, the dsRNA polynucleotides are of one or more defined lengths of about 355 bp.

[0047] In some embodiments, the dsRNA polynucleotides are derived from a reporter gene. In some embodiments, the dsRNA polynucleotides are derived from any one of beta-galactosidase (e.g., NCBI Accession Nos: M38327 or KF924755 or variations thereof), luciferase (e.g., NCBI Accession Nos: M65067.1, M15077.1, M25666.1, L04648.1, M63501.1, M26194.1, Z69619.1, Z49891.1, X66919.1, L39928.1, L39929.1, AJ488147.1, AY181996.1, AB261988.1, AB261987.1, AB261986.1, AB261985.1, AB762768.1 or S61961.1 or variations thereof), betalactamase (e.g., NCBI Accession Nos: NG_081784.1, NG_081783.1, NG_081782.1, NG_081781.1, NG_081780.1, NG_081774.1, NG_081772.1, NG_081771.1, NG_081770.1, NG_081769.1, NG_081768.1, NG_081767.1, NG_081766.1, NG_081765.1, NG_081764.1, NG_081762.1, NG_081761.1, NG_081760.1, NG_081759.1 or NG_081758.1, or variations thereof), alkaline phosphatase (e.g., NCBI Accession Nos: L36230.1, AJ278740.1, AH005272.2, M33634.1, J03572.1, X16028.1, M33965.2, M54798.1, M33536.1, J05005.1, M13345.1, J03930.1, J03252.1, J04948.1, M18443.1, M77507.1, X55958.1, X13409.1, L27993.1, X56656.1, X98402.1, Y00512.1, Z48801.1, AI309568.1, AJ296089.1, AB012643.1 , X04586.1, AJ012458.1 or XM_009310189.1, or variations thereof) and green fluorescence protein (GFP) (e.g., , NCBI Accession Nos: LN515608.1 or KJ668651.1, or variations thereof). In some embodiments, the dsRNA polynucleotides are derived from a luciferase gene. In some embodiments, the dsRNA polynucleotides are derived from a firefly luciferase reporter gene (e.g., NCBI Accession No: M15077.1 or variations thereof).

[0048] In some embodiments, the dsRNA standard solution comprises the dsRNA polynucleotides at a starting concentration of about 1 mg/ml before dilution. In some embodiments, the dsRNA standard solution comprises firefly luciferase dsRNA at a concentration of about 1 mg/ml before dilution.

[0049] In some embodiments, starting concentration of the dsRNA standard solution from which the remaining dilutions are generated, comprises between about 1 pg/ml to about 10 pg/ml (e.g., about 1 pg/ml to about 2 pg/ml, about 2 g/ml to about 3 g/ml, about 3 |ig/ml to about 4 pg/ml, about 4 pg/ml to about 5 pg/ml, about 5 pg/ml to about 6 pg/ml, about 6 pg/ml to about 7 pg/ml, about 7 pg/ml to about 8 pg/ml, about 8 pg/ml to about 9 pg/ml, about 9 pg/ml to about 10 pg/ml, about 1 pg/ml to about 9 Lig/ml, about 2 pg/ml to about 10 pg/ml, about 2 pg/ml to about 9 pg/ml, about 3 pg/ml to about 8 pg/ml, about 4 pg/ml to about 7 pg/ml, about 5 pg/ml to about 8 Lig/ml, about 4 pg/ml to about 6 pg/ml, about 3 pg/ml to about 5 pg/ml, or about 2 pg/ml to about 4 pg/ml and all integers including and in between about 1 pg/ml to about 10 pg/ml). In some embodiments, starting concentration of the dsRNA standard solution from which, the remaining dilutions are generated, comprises about 3 pg/ml.

[0050] In some embodiments, the remaining dilutions of the standard solution are generated from the starting concentration by serial dilution.

[0051] In some embodiments, the dilutions of the dsRNA standard solution comprise from about 0.0001 pg/ml to about 5 pg/ml. In some embodiments, the dilutions of the dsRNA standard solution comprise one or more concentrations selected from about 0.000124 pg/ml, about 0.000248 pg/ml, about 0.000497 pg/ml, about 0.000985 pg/ml, about 0.00197 pg/ml, about 0.00395 pg/ml, about 0.0098 pg/ml, about 0.0195 pg/ml, about 0.039 pg/ml, about 0.078 pg/ml, about 0.156 pg/ml, about 0.312 pg/ml, about 0.625 pg/ml, about 1.25 pg/ml, about 2.5 pg/ml and about 5 pg/ml.

[0052] In some embodiments, the dilutions of the dsRNA standard solution comprise from about 0.0029 pg/ml to about 5 pg/ml. In some embodiments, the dilutions of the dsRNA standard solution comprise one or more concentrations selected from about 0.0029 pg/ml, about 0.0058 pg/ml, about 0.0117 pg/ml, about 0.0234 pg/ml, about 0.0468 pg/ml, about 0.0937 pg/ml, about 0.1875 pg/ml, about 0.375 pg/ml, about 0.75 pg/ml, about 1.5 pg/ml and about 3 pg/ml.

[0053] In some embodiments, when the sample solution is contacted with a dsRNA capture reagent, the contacting comprises incubating the sample solution with the dsRNA capture reagent for a period of time. In some embodiments, when the sample solution is contacted with a dsRNA detection reagent, the contacting comprises incubating the sample solution with the dsRNA detection reagent for a period of time. Thus, contacting the sample solution with a dsRNA capture reagent and a dsRNA detection reagent can comprise incubating the sample solution with the dsRNA capture reagent for a period of time then incubating the sample solution with the dsRNA detection reagent for a period of time. Washes, rinses, or other steps may be introduced between the contacting/incubating steps, i.e., between contacting with the capture reagent and contacting with the detection reagent. In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent for a period of about 1-4 hours (e g., about 1-1.5 hours, about 1.5 -2 hours, about 2-2.5 hours, about 2.5-3 hours, about 3-3.5 hours, about 3.5-4 hours, about 1-3 hours, about 2-4 hours, about 1-4 hours, about 1-3 hours, about 3-5 hours, about 1.5-2.5 hours, or about 2.5-3.5 hours and all integers including and in between about 1-4 hours). In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent for a period of about 2-4 hours (e.g., about 2-2.5 hours, about 2.5-3 hours, about 3—3.5 hours, about 3.5-4 hours, about 2-3.5 hours, about 2.5-4 hours, about 2-3 hours, about 3-4 hours or about 2 5-3.5 hours and all integers including and in between 2-4 hours). In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent for a period of about 1-3 hours (e.g., about 1-1.5 hours, about 1.5—2 hours, about 2-2.5 hours, about 2.5-3 hours, about 1-2.5 hours, about 1.5-3 hours, about 1.5-2.5 hours or about 1.5-3 hours, and all integers including and in between 2-4 hours).

[0054] In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent under shaking at between about 300 to about 500 rotations per minute (rpm) (e.g., about 300 to about 350 rpm, about 350 to about 400 rpm, about 400 to about 450 rpm, about 450 to about 500 rpm, about 300 to about 450 rpm, about 350 rpm to about 500 rpm, about 350 rpm to about 450 rpm or about 400 rpm to about 500 rpm, and all integers including and in between about 300 to about 500 rpm. In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent under shaking at about 450 rpm.

[0055] In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent for a period of about 1-3 hours (e.g., about 1-1.5 hours, about 1.5-2 hours, about 2-2.5 hours, about 2.5-3 hours, about 1-2.5 hours, about 1.5-3 hours, about 1.5-2.5 hours or about 1.5-3 hours and all integers including and in between 2-4 hours). In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent for a period of about 1-2 hours (e.g., about 1-1.5 hours or about 1.5-2 hours, and all integers including and in between 1-2 hours). [0056] In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent under shaking at between about 300 to about 500 rotations per minute (rpm) (e.g., about 300 to about 350 rpm, about 350 to about 400 rpm, about 400 to about 450 rpm, about 450 to about 500 rpm, about 300 to about 450 rpm, about 350 rpm to about 500 rpm, about 350 rpm to about 450 rpm or about 400 rpm to about 500 rpm, and all integers including and in between about 300 to about 500 rpm). In some embodiments, the contacting/incubating steps further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent under shaking at about 450 rpm.

[0057] In one aspect, the present disclosure also provides a composition for use as a dsRNA standard solution, the composition comprising dsRNA polynucleotides of one or more defined lengths in base pairs (bp) and a molecular crowding agent.

[0058] In some embodiments of the composition of the present disclosure, the molecular crowding agent comprises a double-stranded conformation-stabilizing polymer. In some embodiments of the composition of the present disclosure, the molecular crowding agent comprises polyethylene glycol (PEG), dextran, or Ficoll" . In some embodiments of the composition of the present disclosure, the molecular crowding agent is present at a concentration effective to stabilize a double-stranded conformation of the dsRNA polynucleotides.

[0059] In some embodiments of the composition of the present disclosure, the molecular crowding agent is PEG-8000. In some embodiments of the composition of the present disclosure, the molecular crowding agent is PEG-400, PEG-800, PEG-1500, PEG-3000, PEG-6000, or PEG- 8000. In some embodiments of the composition of the present disclosure, the PEG-8000 is present in the dsRNA standard solution at a concentration of about 0.01% v/v to about 50% v/v (e.g., about 0.01% v/v to about 0.05% v/v, about 0.05% v/v to about 0.1% v/v, about 0.1% v/v to about 0.5% v/v, about 0.5% v/v to about 1% v/v, about 1% v/v to about 5% v/v, about 5% v/v to about 10% v/v, about 10% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, about 25% v/v to about 30% v/v, about 30% v/v to about 35% v/v, about 35% v/v to about 40% v/v, about 40% v/v to about 45% v/v, about 45% v/v to about 50% v/v, about 0.01% v/v to about 45% v/v, about 0.05% v/v to about 50% v/v, about 0.1% v/v to about 40% v/v, about 0.5% v/v to about 35% v/v, about 1% v/v to about 30% v/v, about 5% v/v to about 25% v/v, about 10% v/v to about 20% v/v, about 10% v/v to about 15% v/v or about 15% v/v to about 20% v/v, and all percentages including and in between about 0.01% v/v to about 50% v/v) before dilution.

[0060] In some embodiments of the composition of the present disclosure, the PEG-8000 is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 15% v/v (e.g., about 0.1% v/v to about 0.25% v/v, about 0.25% v/v to about 0.5% v/v, about 0.5% v/v to about 0.75% v/v, about 0.75% v/v to about 1% v/v, about 1% v/v to about 1.5% v/v, about 1.5% v/v to about 2% v/v, about 2% v/v to about 2.5% v/v, about 2.5% v/v to about 5% v/v, about 5% v/v to about 7.5% v/v, about 7.5% v/v to about 10% v/v, about 10% v/v to about 12.5% v/v, about 12.5% v/v to about 15% v/v, about 0.1% v/v to about 10% v/v, about 0.25% v/v to about 15% v/v, about 0.5% v/v to about 12.5% v/v, about 0.75% v/v to about 10% v/v, about 1% v/v to about 7.5% v/v, about 1.5% v/v to about 5% v/v, about 2% v/v to about 5% v/v, about 1% v/v to about 2.5% v/v, about 1.5% v/v to about 2.5% v/v and all percentages including and in between about 0.1% v/v to about 15% v/v) before dilution.

[0061] In some embodiments of the composition of the present disclosure, the molecular crowding agent is a dextran. In some embodiments of the composition of the present disclosure, the molecular crowding agent is a dextran-40 or dextran-70. In some embodiments, the dextran is present in the dsRNA standard solution at a concentration of about 0.01% v/v to about 50% v/v (e.g., about 0.01% v/v to about 0.05% v/v, about 0.05% v/v to about 0.1% v/v, about 0.1% v/v to about 0.5% v/v, about 0.5% v/v to about 1% v/v, about 1% v/v to about 5% v/v, about 5% v/v to about 10% v/v, about 10% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, about 25% v/v to about 30% v/v, about 30% v/v to about 35% v/v, about 35% v/v to about 40% v/v, about 40% v/v to about 45% v/v, about 45% v/v to about 50% v/v, about 0.01% v/v to about 45% v/v, about 0.05% v/v to about 50% v/v, about 0.1% v/v to about 40% v/v, about 0.5% v/v to about 35% v/v, about 1% v/v to about 30% v/v, about 5% v/v to about 25% v/v, about 10% v/v to about 20% v/v, about 10% v/v to about 15% v/v or about 15% v/v to about 20% v/v, and all percentages including and in between about 0.01% v/v to about 50% v/v) before dilution.

[0062] In some embodiments of the composition of the present disclosure, the dilutions of the dsRNA standard solution comprise the dextran at a concentration of about 0.1% v/v to about 25% v/v (e.g., about 0.1% v/v to about 0.25% v/v, about 0.25% v/v to about 0.5% v/v, about 0.5% v/v to about 0.75% v/v, about 0.75% v/v to about 1% v/v, about 1% v/v to about 1.5% v/v, about 1.5% v/v to about 2% v/v, about 2% v/v to about 2.5% v/v, about 2.5% v/v to about 5% v/v, about 5% v/v to about 7.5% v/v, about 7.5% v/v to about 10% v/v, about 10% v/v to about 12.5% v/v, about 12.5% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, or about 0.1% v/v to about 20% v/v, about 0.25% v/v to about 25% v/v, about 0.5% v/v to about 15% v/v, about 0.75% v/v to about 12.5% v/v, about l% v/v to about 10% v/v, about 1.5% v/v to about 7.5% v/v, about 2% v/v to about 5% v/v, about 2.5% v/v to about 7.5% v/v, about 1.5% v/v to about 2.5% v/v and all percentages including and in between about 0.1% v/v to about 25% v/v) before dilution,

[0063] In some embodiments of the composition of the present disclosure, the molecular crowding agent is Ficoll ¹ ®. In some embodiments of the composition of the present disclosure, the molecular crowding agent is Ficoll-Paque®, Ficoll-Paque^PLUS, Ficoll-Paque®Premium, and Ficoll®400. In some embodiments of the composition of the present disclosure, the Ficoll® is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 50% v/v (e.g., about 0.1% v/v to about 0.25% v/v, about 0.25% v/v to about 0.5% v/v, about 0.5% v/v to about 0.75% v/v, about 0.75% v/v to about 1% v/v, about 1% v/v to about 1.5% v/v, about 1.5% v/v to about 2% v/v, about 2% v/v to about 2.5% v/v, about 2.5% v/v to about 5% v/v, about 5% v/v to about 7.5% v/v, about 7.5% v/v to about 10% v/v, about 10% v/v to about 12.5% v/v, about 12.5% v/v to about 15% v/v, about 15% v/v to about 20% v/v, about 20% v/v to about 25% v/v, about 25% v/v to about 30% v/v, about 30% v/v to about 35% v/v, about 35% v/v to about 40% v/v, about 40% v/v to about 45% v/v, about 45% v/v to about 50% v/v, about 0.1% v/v to about 45% v/v, about 0.25% v/v to about 50% v/v, about 0.5% v/v to about 40% v/v, about 0.75% v/v to about 35% v/v, about 1% v/v to about 30% v/v, about 1.5% v/v to about 25% v/v, about 2% v/v to about 20% v/v, about 2.5% v/v to about 15% v/v, about 5% v/v to about 12.5% v/v, about 7.5% v/v to about 12.5% v/v or about 5% v/v to about 10% v/v, and all percentages including and in between about 0.1% v/v to about 50% v/v) before dilution.

[0064] In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides comprise one or more defined lengths of about 50 bp to about 10,000 bp (about 50 bp to about 100 bp, about 100 bp to about 250 bp, about 250 bp to about 500 bp, about 500 bp to about 750 bp, about 750 bp to about 1000 bp, about 1000 bp to about 2000 bp, about 2000 bp to about 3000 bp, about 3000 bp to about 4000 bp, about 4000 bp to about 5000 bp, about 5000 bp to about 6000 bp, about 6000 bp to about 7000 bp, about 7000 bp to about 8000 bp, about 8000 bp to about 9000 bp, about 9000 bp to about 10,000 bp, about 50 bp to about 9000 bp, about 100 bp to about 10,000 bp, about 100 bp to about 9000 bp, about 100 bp to about 8000 bp, about 250 bp to about 7000 bp, about 500 bp to about 6000 bp, about 750 bp to about 5,000 bp, about 1000 bp to about 4,000 bp, about 2000 bp to about 4,000 bp, about 250 bp to about 1000 bp, about 100 bp to about 250 bp, and all integers including and in between about 50 bp to about 10,000 bp). [0065] In some embodiments of the composition of the present disclosure, the one or more defined lengths of the dsRNA polynucleotides are in increments of about 5 bp, increments of about 10 bp, increments of about 20 bp, increments of about 50 bp, increments of about 100 bp, and/or increments of about 1,000 bp. In some embodiments, the dsRNA polynucleotides are of one or more defined lengths selected from one or more of about 50 bp, about 60 bp, about 70 bp, about 80 bp, about 90 bp, about 100 bp, about 150 bp, about 200 bp, about 250 bp, about 300 bp, about 350 bp, about 400 bp, about 450 bp, about 500 bp, about 550 bp, about 600 bp, about 650 bp, about 700 bp, about 750 bp, about 800 bp, about 850 bp, about 900 bp, about 950 bp, about 1,000 bp, about 1,100 bp, about 1,200 bp, about 1,300 bp, about 1,400 bp, about 1,500 bp, about 1,600 bp, about 1,700 bp, about 1,800 bp, about 1,900 bp, about 2,000 bp, about 2,100 bp, about 2,200 bp, about 2,300 bp, about 2400 bp, about 2,500 bp, about 2,600 bp, about 2,700 bp, about 2,800 bp, about 2,900 bp, about 3,000 bp, about 3,100 bp, about 3,200 bp, about 3,300 bp, about 3,400 bp, about 3,500 bp, about 3,600 bp, about 3,700 bp, about 3,800 bp, about 3,900 bp, about 4,000 bp, about 41,00 bp, about 4,200 bp, about 4,300 bp, about 4,400 bp, about 4,500 bp, about 4,600 bp, about 4,700 bp, about 4,800 bp, about 4,900 bp, about 5,000 bp, about 5,100 bp, about 5,200 bp, about 5,300 bp, about 5,400 bp, about 5,500 bp, about 5,600 bp, about 5,700 bp, about 5,800 bp, about 5,900 bp, about 6,000 bp, about 6,100 bp, about 6,200 bp, about 6,300 bp, about 6,400 bp, about 6,500 bp, about 6,600 bp, about 6,700 bp, about 6,800 bp, about 6,900 bp, about 7,000 bp, about 7,100 bp, about 7,200 bp, about 7,300 bp, about 7,400 bp, about 7,500 bp, about 7,600 bp, about 7,700 bp, about 7,800 bp, about 7,900 bp, about 8,000 bp, about 8,100 bp, about 8,200 bp, about 8,300 bp, about 8,400 bp, about 8,500 bp, about 8,600 bp, about 8,700 bp, about 8,800 bp, about 8,900 bp, about 9,000 bp, about 9,100 bp, about 9,200 bp, about 9,300 bp, about 9,400 bp, about 9,500 bp, about 9,600 bp, about 9,700 bp, about 9,800 bp, about 9,900 bp, and about 10,000 bp.

[0066] In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are of one or more defined lengths of about 10 bp to about 1000 bp (e.g., about 10 bp to about 25 bp, about 25 bp to about 50 bp, about 50 bp to about 100 bp, about 100 bp to about 150 bp, about 150 bp to about 200 bp, about 200 bp to about 300 bp, about 300 bp to about 400 bp, about 400 bp to about 500 bp, about 500 bp to about 600 bp, about 600 bp to about 700 bp, about 700 bp to about 800 bp, about 800 bp to about 900 bp, about 900 bp to about 1000 bp, about 10 bp to about 900 bp, about 25 bp to about 900 bp, about 25 bp to about 800 bp, about 50 bp to about 700 bp, about 100 bp to about 600 bp, about 150 bp to about 500 bp, about 200 bp to about 400 bp, about 100 bp to about 300 bp, about 300 bp to about 500 bp and all integers including and in between about 10 bp to about 1000 bp).

[0067] In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are of one or more defined lengths of about 100 bp to about 500 bp (e.g., about 100 bp to about 200 bp, about 200 bp to about 300 bp, about 300 bp to about 400 bp, about 400 bp to about 500 bp, about 100 bp to about 400 bp, about 200 bp to about 500 bp, about 100 bp to about 300 bp, about 200 bp to about 400 bp or about 300 bp to about 500 bp and all integers including and in between about 100 bp to about 500 bp). In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are of one or more defined lengths of about 200 bp to about 400 bp (e.g., about 200 bp to about 250 bp, about 200 bp to about 250 bp, about 250 bp to about 300 bp, about 300 bp to about 350 bp, about 350 bp to about 400 bp, about 200 bp to about 350 bp, about 250 bp to about 400 bp, about 250 bp to about 350 bp, about 300 bp to about 400 bp, about 200 bp to about 300 bp, about 300 bp to about 400 bp, about 400 bp to about 500 bp or about 250 bp to about 350 bp, and all integers including and in between about 200 bp to about 400 bp). In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are of defined lengths of about 355 bp.

[0068] In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are derived from a reporter gene. In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are derived from any one of beta-galactosidase, luciferase, beta-lactamase, alkaline phosphatase and GFP (green fluorescence protein). In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are derived from a luciferase gene. In some embodiments of the composition of the present disclosure, the dsRNA polynucleotides are derived from a firefly luciferase reporter gene.

[0069] In some embodiments of the composition of the present disclosure, the dsRNA standard solution comprises the dsRNA polynucleotides at a starting concentration of about 1 mg/ml before dilution. In some embodiments of the composition of the present disclosure, the dsRNA standard solution comprises firefly luciferase dsRNA at a concentration of about 1 mg/ml before dilution.

[0070] In one aspect, the present disclosure provides a kit for quantitative measurement of dsRNA present in a sample solution, the kit comprising: (a) a dsRNA standard solution comprising dsRNA polynucleotides and a molecular crowding agent of the composition of the present disclosure; and (b) one or more reagents for carrying out an assay for detecting dsRNA present in a sample solution.

[0071] In some embodiments, the kit of the present disclosure is for an enzyme linked immunosorbent assay (ELISA) assay. In some embodiments, the ELISA comprises any one of a sandwich ELISA assay or a direct ELISA. In some embodiments, the method comprises a sandwich ELISA assay.

[0072] In some embodiments of the kit of the present disclosure, the one or more reagents for carrying out an assay for detecting dsRNA comprise a dsRNA capture reagent, a dsRNA detection reagent, a secondary detection reagent or a combination thereof. In some embodiments of the kit of the present disclosure, the one or more reagents for carrying out an assay for detecting dsRNA comprise a dsRNA capture reagent. In some embodiments of the kit of the present disclosure, the one or more reagents for carrying out an assay for detecting dsRNA comprise a dsRNA capture reagent and a dsRNA detection reagent. In some embodiments of the kit of the present disclosure, the one or more reagents for carrying out an assay for detecting dsRNA comprise a dsRNA capture reagent, a dsRNA detection reagent, and a secondary detection reagent.

[0073] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is immobilized on a solid substrate. In some embodiments, the solid substrate is any one of polystyrene, polyethylene, polyacrylamide, agarose, glass, or silicone rubber. In some embodiments, the solid substrate is polystyrene.

[0074] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that specifically binds dsRNA. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of J2, K2, 9D5 or KI antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of J2 or K2 antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as J2 antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as K2 antibody or a fragment thereof. [0075] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is any one of J2, K2, 9D5 or KI antibody. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is any one of J2 or K2 antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is a J2 antibody. In some embodiments, the capture reagent is a K2 antibody or a fragment thereof.

[0076] In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is an antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2, J2, 9D5 or KI antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2 or J2 antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as K2 antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is an antibody or fragment thereof that has the same antigen binding specificity as J2 antibody or a fragment thereof.

[0077] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof bound to Protein A immobilized on the solid substrate. In some embodiments, the dsRNA capture reagent is any one of an antibody or fragment thereof bound to Protein A immobilized on the solid substrate.

[0078] In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is any one of J2, K2, 9D5 or KI antibody. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is any one of J2 or K2 antibody. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is a J2 antibody. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is a K2 antibody.

[0079] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof bound to the solid substrate. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof bound to any one of Protein A, Protein G or Protein L or a combination thereof, immobilized on the solid substrate. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof bound to Protein A immobilized on the solid substrate. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is any one of J2, K2, 9D5 or KI antibody or a fragment thereof, bound to any one of Protein A, Protein G or Protein L or a combination thereof, immobilized on the solid substrate. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is any one of J2, K2, 9D5 or KI antibody or a fragment thereof, bound to any one of Protein A immobilized on the solid substrate. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is any one of J2 antibody or a fragment thereof, bound to any one of Protein A immobilized on the solid substrate. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is any one of K2 antibody or a fragment thereof, bound to any one of Protein A immobilized on the solid substrate.

[0080] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is used at a concentration of about 0.1 pg/ml to about 1.0 pg/ml (e.g., about 0.1 pg/ml to 0.2 pg/ml, about 0.2 pg/ml to 0.3 pg/ml, about 0.3 pg/ml to 0.4 pg/ml, about 0.4 pg/ml to 0.5 pg/ml, about 0.5 pg/ml to 0.6 pg/ml, about 0.6 pg/ml to 0.7 pg/ml, about 0.7 pg/ml to 0.8 pg/ml, about 0.8 pg/ml to 0.9 pg/ml, about 0.9 pg/ml to 1 pg/ml, about 0.1 pg/ml to 0.9 pg/ml, about 0.2 pg/ml to 1 pg/ml, about 0.1 pg/ml to 0.9 pg/ml, about 0.2 pg/ml to 0.8 pg/ml or about 0.3 pg/ml to 0.7 pg/ml, about 0.4 pg/ml to 0.6 pg/ml, about 0.5 pg/ml to 0.7 pg/ml and all integers including and in between about 0.1 pg/ml to about 1.0 pg/ml and all integers including and in between about 0.1 pg/ml to about 1.0 pg/ml). In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is used at a concentration of about 0.5 pg/ml. In some embodiments, the dsRNA capture reagent is used at a concentration of 0.5 pg/ml.

[0081] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that specifically binds dsRNA and does not specifically bind Protein A, Protein G or Protein L or a combination thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that specifically binds dsRNA and does not specifically bind Protein A. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2, J2, 9D5, or KI antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as any one of K2 or J2 antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as K2 antibody or a fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is an antibody or fragment thereof that has the same antigen binding specificity as J2 antibody or a fragment thereof.

[0082] In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is an IgM isotype antibody or fragment thereof that specifically binds dsRNA and does not specifically bind Protein A. In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is K2 IgM isotype antibody or antigen-binding fragment thereof.

[0083] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is KI antibody or fragment thereof, and the dsRNA detection reagent is K2 antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is KI antibody or fragment thereof, and the dsRNA detection reagent is J2 antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is KI antibody or fragment thereof, and the dsRNA detection reagent is 9D5 antibody or fragment thereof.

[0084] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is K2 antibody or fragment thereof, and the dsRNA detection reagent is KI antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is K2 antibody or fragment thereof, and the dsRNA detection reagent is J2 antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is K2 antibody or fragment thereof, and the dsRNA detection reagent is 9D5 antibody or fragment thereof.

[0085] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is J2 antibody or fragment thereof, and the dsRNA detection reagent is KI antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is J2 antibody or fragment thereof, and the dsRNA detection reagent is K2 antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is J2 antibody or fragment thereof, and the dsRNA detection reagent is 9D5 antibody or fragment thereof. [0086] In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is 9D5 antibody or fragment thereof, and the dsRNA detection reagent is KI antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is 9D5 antibody or fragment thereof, and the dsRNA detection reagent is K2 antibody or fragment thereof. In some embodiments of the kit of the present disclosure, the dsRNA capture reagent is 9D5 antibody or fragment thereof, and the dsRNA detection reagent is J2 antibody or fragment thereof.

[0087] In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is used at a dilution of about 1:20 to about 1: 100 (e.g., about 1 :20 to about 1 :30, about 1:30 to about 1 :40, about 1 :40 to about 1 :50, about 1 :50 to about 1 :60, about 1 :60 to about 1 :70, about 1 :70 to about 1:80, about 1 :80 to about 1 :90, about 1 :90 to about 1 : 100, about 1 :20 to about 1 :90, about 1 :30 to about 1 : 100, about 1 : 30 to about 1 :90, about 1 :40 to about 1 :80, about 1 :50 to about 1 :70, about 1 :40 to about 1 :60, about 1 :30 to about 1 :50 and all ratios including and in between about 1 :20 to about 1 : 100). In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is used at a dilution of about 1 : 100.

[0088] In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is used at a dilution of about 0.05 g/ml to about 10 pg/ml (e.g., about 0.05 Lig/ml to about 0.1 pg/ml, about 0.1 pg/ml to about 0.5 pg/ml, about 0.5 pg/ml to about 1 pg/ml, about 1 pg/ml to about 2 g/ml, about 2 pg/ml to about 5 pg/ml, about 5 pg/ml to about 10 pg/ml, about 0.05 pg/ml to about 5 pg/ml, about 0.1 pg/ml to about 1 pg/ml, about 0.5 pg/ml to about 2 pg/ml, about 0.05 pg/ml to about 2 pg/ml, and all ratios including and in between about 1 :20 to about 1 : 100). In some embodiments of the kit of the present disclosure, the dsRNA detection reagent is used at a dilution of about 0.05 pg/ml to about 10 pg/ml.

[0089] In some embodiments of the kit of the present disclosure, the secondary detection reagent is an antibody or fragment thereof that specifically binds the dsRNA detection reagent. In some embodiments of the kit of the present disclosure, the secondary detection reagent comprises a reporter moiety. In some embodiments of the kit of the present disclosure, the reporter moiety is a chromogenic enzyme. In some embodiments of the kit of the present disclosure, the reporter moiety is a chromogenic enzyme. In some embodiments of the kit of the present disclosure, the chromogenic enzyme is a horse-radish peroxidase (HRP), an alkaline phosphatase (AP), a -a galactosidase, an acetylcholinesterase, or a catalase. In some embodiments of the kit of the present disclosure, the chromogenic enzyme is an HRP or an AP. In some embodiments of the kit of the present disclosure, the chromogenic enzyme is an HRP.

[0090] In some embodiments of the kit of the present disclosure, the secondary detection reagent is an HRP-conjugated anti-mouse p-chain F(ab’)2 fragment. In some embodiments of the kit of the present disclosure, the secondary detection reagent is an AP-conjugated anti-mouse p- chain F(ab’)2 fragment.

[0091] In one aspect, the present disclosure also provides a method of screening a set of procedures for reducing dsRNA content of a sample solution comprising a known amount of dsRNA, the method comprising: (a) performing each of the set of procedures on an amount of the sample solution for an amount of time to form a set of test sample solutions, the amount of sample solution and amount of time being same for each compound of the set; (b) quantifying the amount of dsRNA in each test sample solution using the method of the present disclosure; and (c) determining if a procedure of the set is effective in reducing dsRNA from the sample if the concentration of dsRNA in the corresponding test sample solution is reduced by at least 90% (e.g., at least 90%, at least 95%, at least 98%, at least 99% or 100%), as compared to the sample solution before contacting with the compound.

[0092] In some embodiments, one or more of the procedures of reducing dsRNA content of a sample solution of the set comprises: (a) contacting an amount of the sample solution with a compound; (b) maintaining an amount of the sample solution under a condition; (c) contacting an amount of the sample solution with an affinity chromatography medium; or (d) passing an amount of the sample solution through a filtration medium.

[0093] In some embodiments, the procedures of reducing dsRNA content of a sample solution of the set comprises contacting an amount of the sample solution with a compound that is a chaotropic agent or an enzyme. (See, for example, WO 2021158789 Al, incorporated herein by reference.) In some embodiments, the chaotropic agent is any one of urea, formamide, sodium salicylate, ethanol, sodium perchlorate, arginine, n-butanol, thiourea, and 2-propanol. In some embodiments, the enzyme is a ribonuclease (RNAse).

[0094] In some embodiments, the procedures of reducing dsRNA content of a sample solution of the set comprises maintaining an amount of the sample solution under a condition defined by temperature, a pH, a salt concentration, or a combination thereof. [0095] In some embodiments, the procedures of reducing dsRNA content of a sample solution of the set comprises contacting an amount of the sample solution with an affinity chromatography medium. In some embodiments, the affinity chromatography medium specifically binds the dsRNA. In some embodiments, the affinity chromatography medium comprises a binding reagent that binds specifically dsRNA. In some embodiments, the affinity chromatography medium comprises an antibody or a fragment thereof that specifically binds dsRNA. In some embodiments, the affinity chromatography medium comprises cellulose.

[0096] In some embodiments, one or more of the procedures of reducing dsRNA content of a sample solution of the set comprises passing an amount of the sample solution through a filtration medium. In some embodiments, the filtration medium comprises a pore size that only allows dsRNA molecules to pass through.

[0097] In one aspect, the present disclosure also provides a method of correlating an amount of dsRNA in a sample solution with immunogenicity of the sample solution, the method comprising: (a) quantitatively measuring the amount of dsRNA present in the sample dilutions using a method of the present disclosure; (b) quantitatively measuring the level of immune activation induced by the sample by conducting an in vitro immune activation assay using the sample; and (c) determining the amount of dsRNA to be non-immunogenic if the corresponding level of immune activation induced by the sample as determined in (b) is less than or equal to a pre-determined value.

[0098] In some embodiments, the in vitro immune activation assay is an in vitro innate immune receptor pathway activation assay. In some embodiments, the in vitro immune activation assay is selected from any one of a RIG-I activation assay, an MDA-5 activation assay and a TLR-3 activation assay.

[0099] In some embodiments, the in vitro innate immune receptor activation assay comprises contacting the sample solution with a host cell comprising a reporter gene that is operably linked to a promoter that is inducible by activation of an innate immune receptor by dsRNA such that activation of an innate immune receptor results in expression of the reporter gene. In some embodiments, the reporter gene is a luciferase encoding gene or a fluorescent protein encoding gene. In some embodiments, the reporter gene is a firefly luciferase encoding gene. In some embodiments, the reporter gene is any one of a green fluorescent protein, a red fluorescent protein, a yellow fluorescent protein or a cyan fluorescent protein encoding gene. [0100] In some embodiments, the host cell expresses an innate immune receptor. In some embodiments, the innate immune receptor is activated by both low and high density dsRNA. In some embodiments, the immune activation results in a detectable signal, wherein the level of immune activation is directly proportional to the intensity of the detectable signal. In some embodiments, the detectable signal is a fluorescence signal or a chemiluminescence signal.

[0101] In some embodiments, the detectable signal is a luminescence signal of wavelength 400 nm to 700 nm. In some embodiments, the detectable signal is a fluorescence signal of wavelength 400 nm to 700 nm.

[0102] In some embodiments, the innate immune receptor is activated by low density dsRNA. In some embodiments, the innate immune receptor is activated by high density dsRNA. In some embodiments, the level of immune activation induced by the sample is directly proportional to the amount of dsRNA.

Definitions

[0103] Before describing the present invention in detail, it is to be understood that this invention is not limited to particular compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in this specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a molecule” optionally includes a combination of two or more such molecules, and the like.

[0104] The term “macromolecular crowding” or “crowding” refers to a phenomenon that alters the properties of molecules, e.g., double stranded nucleic acid, in a solution. In living cells, high concentrations of macromolecules such as proteins reduce the volume of solvent available for other molecules in the solution (excluded volume effect), which results in increasing the effective concentrations of the other molecules. This crowding effect can make molecules in cells behave in radically different ways than they do in extracellular conditions such as in non-cell-based production systems (like in vitro transcription systems, IVTs) or in purified solutions. One approach to mimic the excluded volume effects seen in cellular environments in extracellular environments and/or non-cell-based systems is to use so-called macromolecular crowding agents. [0105] The term “crowding agent” or a “molecular crowding agent” may refer to chemicals that are inert, non-charged polymers of certain sizes (e.g., dextrans, Ficoll) and that occupy space but do not interact with target proteins (Bohrer et al. 1984; Venturoli and Rippe 2005; Zhou et al. 2008), and thus may cause macromolecular crowding in extracellular environments or non-cell- based systems. Crowding agents may absorb little light in the protein spectral regions. Crowding agents may be dissolvable in high concentrations (e g., up to 400 mg/ml). Crowding agents may increase the rate of enzymatic reactions, alter reaction products, protect macromolecules from thermal denaturation, accelerate protein folding, and/or facilitate nucleic acids renaturation.

[0106] The term “double-stranded conformation-stabilizing polymer” may refer to a type of crowding agents that stabilize folded RNA (and DNA) conformations entropically due to the excluded volume effect. Double-stranded conformation stabilizing polymers, such as PEGs, may increase RNA (and DNA) stability and improve their binding and detection by various detecting reagents.

[0107] The term “polyethylene glycol (PEG)” may refer to a polyether compound derived from petroleum, also known as polyethylene oxide (PEG) or polyoxyethylene (POE), depending on its molecular weight. The structure of PEG is commonly expressed as H-(O-CH2-CH2)n-OH. The different grades of PEG used in pharmaceutical industry and experimental medicine based on their molecular weight are PEG-400, PEG-800, PEG-1500, PEG-3000, PEG-6000, or PEG-8000. PEGs with molecular weights >5 kDa are typically used for conjugation to small molecules, siRNA, and peptides, and hydrogel formation.

[0108] The term “dextran” may refer to branched poly-a-d-glucosides of microbial origin having glycosidic bonds predominantly C-l C-6. The structure of dextran is commonly expressed as H(CeEIio05)xOH. Dextran chains are of varying lengths. It can occur in various molecular weights including high-molecular weight dextrans like dextran-40 (MW: 40,000 Da), dextran-70 (>60,000 Da), and dextran derivatives such as dextran sulfate and cationic dextran.

[0109] The term “Ficoll” or “Ficoll®” may refer to a neutral, highly branched, high- mass, hydrophilic polysaccharide prepared by reaction of the polysaccharide with epichlorohydrin, and which dissolves readily in aqueous solutions. Ficoll radii range from 2-7 nm. Ficoll is a registered trademark owned by GE Healthcare companies. The different Ficoll grades available are Ficoll-Paque®, Ficoll-Paque®PLUS, Ficoll-Paque®Premium, and Ficoll®400.

[0110] The term “coating agent” or “blocking agent” may refer to blocking agent that binds non-specifically to and saturates the binding sites of ELISA plates, to prevent unwanted binding of the free ligand to the excess sites on the wells of the plate. Examples of appropriate blocking agents for this purpose include, e.g., gelatin, bovine serum albumin, egg albumin, casein, and nonfat milk. Typically, the ELISA plate is contacted with a blocking agent under conditions of ambient temperatures for about 1-4 hours, preferably about 1 to 3 hours, or overnight at 0-4° C.

[OHl] The term “detecting” is used in the broadest sense to include both qualitative and quantitative measurements of a target molecule. In one aspect, the detecting methods as described herein may be used to identify the mere presence of dsRNA in a sample. In another aspect, the methods may be used to test whether dsRNA in a sample is at a detectable level. In yet another aspect, the methods can be used to quantify the amount of dsRNA in a sample and further to compare the dsRNA levels from different samples or in the same sample before and after being subjected to one or more procedures.

[0112] The term “sample” or “drug substance” may refer to a composition or a solution comprising one or more mRNA(s) or a siRNA/anti-sense oligonucleotide(s) (ASO(s)) or other solution for which determination of dsRNA content may be desirable.

[0113] The term “antibody” herein is used in the broadest sense and specifically covers intact monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies) formed from at least two intact antibodies, and antibody fragments so long as they exhibit the desired biological activity.

[0114] “Antibody fragments” comprise a portion of an antibody, preferably comprising the antigen-binding or variable region thereof. Examples of antibody fragments include Fab, Fab', F(ab')2, and Fv fragments; diabodies; linear antibodies; single-chain antibody molecules; and multispecific antibodies formed from antibody fragments.

[0115] The term “Enzyme-linked immunosorbent assays (ELISAs)” for various antigens include those based on colorimetry, chemiluminescence, and fluorometry. ELISAs have been successfully applied in the determination of low amounts of drugs and other antigenic components in various biological samples, involve no extraction steps, and are simple to carry out. The assay described herein is an ELISA that utilizes antibodies as capture reagents and detectable antibodies for dsRNA. In the first step of the assay the sample suspected of containing dsRNA or containing dsRNA is contacted and incubated with the capture (or coat) antibodies so that the capture antibodies capture or bind to the dsRNA so that it can be detected in a detection step. The detection step involves use of the detectable antibody, which, when contacted with sample, binds to the dsRNA, if present, and a detection means is used to detect the label on the antibody (or a secondary binding reagent bound to the detectable antibody) and hence the presence or amount of dsRNA present.

[0116] Where the use of the term “about” is before a quantitative value, the present invention also includes the specific quantitative value itself, unless specifically stated otherwise. As used herein, the term “about” refers to a ± 10% variation from the nominal value unless otherwise indicated or inferred.

[0117] Unless otherwise noted, where the term “between” is used to refer to a numerical range, the range comprises the specified endpoints and every value between the specified endpoints. For example, the range “about 0.01% v/v to about 50% v/v” includes 0.01%, 50 %, and values greater than 0.01% but less than 50 %.

[0118] The use of the term “include,” “includes,” “including,” “have,” “has,” “having,” “contain,” “contains,” or “containing,” including grammatical equivalents thereof, should be understood generally as open-ended and non-limiting, for example, not excluding additional unrecited elements or steps, unless otherwise specifically stated or understood from the context.

EXAMPLES

Materials and methods

[0119] Described herein is a study using the methods of the present disclosure to determine the relative quantity of double-stranded RNA (dsRNA) in a sample solution comprising an mRNA drug substance. This study determines the scope of the disclosed method for determining the purity of the solution comprising mRNA drug substance. The dsRNA is detected by a sandwich ELISA method using J2 and K2 monoclonal antibodies, which are specific for dsRNA, and quantified by comparison to a calibration standard curve of in vitro synthesized Firefly luciferase (FLuc) dsRNA. Details of equipment and materials used for the study described herein are provided below:

Table 1. Equipment Table 2: Materials

Example 1: Procedure for enzyme-linked immunodetection assay (ELISA) for detection and quantification of dsRNA

[0120] Objective: The study described herein describes the optimization and evaluation of an ELISA platform using two monoclonal antibodies, J2 and K2, and buffers with salt and crowding agent concentrations, for detection of dsRNA.

[0121] Study Design and procedure: The dsRNA present in a sample containing the mRNA drug substance is captured and detected in a sandwich ELISA format using two monoclonal antibodies, J2 and K2, that both bind specifically to dsRNA, based on the process flow as described in FIG. 1A. Briefly, an ELISA plate was first coated with Protein A, which was then loaded with the J2 IgG antibody for analyte capture. After RNA samples were allowed to interact with the bound J2 antibody, the K2 antibody was then added for detection. Because K2 is an IgM isotype antibody, it does not bind to the Protein A on the plate and only interacts with the dsRNA present in the sample. To read out the signal, an HRP enzyme-conjugated F(ab’)2 fragment that specifically targets the p-chain of IgM immunoglobulins was added to the ELISA plate. The absence of the Fc region on this F(ab’)2 fragment prevents non-specific interaction with the Protein A, and the target specificity of the antigen-binding region prevents interaction with the J2 IgG antibody, which together leads to accurate quantification of the dsRNA content of the sample with low background. Quantification was achieved by addition of the chromogenic HRP substrate TMB, which can be detected by the absorbance of 450 nm light.

Buffer Preparation

[0122] PBS-T buffer preparation: 50 mL of 20X PBS-T was transferred to a clean nuclease- free or RNaseZAP treated 1 L vessel. RNase-free water was added to 1 L, minimizing formation of bubbles due to detergent in the PBS-T. If excessive foaming occurred, the buffer was set aside to allow foam to subside before resuming and mixed thoroughly. A IX PBS-T solution was prepared by transferring 100 mL of 1 OX PBS to a clean nuclease-free or RNaseZAP treated 1 L vessel, followed by adding RNase-free water to a final volume of 1 L and mixing thoroughly, and could be stored for 4 weeks at room temperature.

[0123] 2% BSA solution preparation: 10 mL of 10% BSA in PBS solution was added to a nuclease-free 50 mL conical tube. IX PBS to 50 mL was added and mix thoroughly. Prepared 2% BSA could be stored for 2 weeks at 2-8°C.

[0124] 50% PEG-8000 solution preparation: 25 g of PEG-8000 was weighed out and transferred to a nuclease-free 50 mL conical tube. RNase-free water was added to a total volume of approximately 35-45 mL and mixed on a rotator until the PEG was fully dissolved, up to overnight. The volume was adjusted to 50 mL with additional RNase-free water and vortexed and inverted repeatedly until thoroughly mixed.

[0125] ELISA Plate Preparation: The plate washer was prepared by running a Quick Prime cycle using water to flush the entire system with 500 mL. The system was primed with wash buffer by running another Quick Prime cycle using PBS-T buffer. A Protein A coated plate was equilibrated to room temperature for approximately 30 minutes. The plate was loaded into the plate washer and the WCELL WASH 96 program was run to rinse every well with 3 cycles of 500 pL of PBS-T buffer. The WCELL WASH 96 program was run again, any remaining buffer in the plate was discarded and the plate was dried thoroughly by striking the plate forcefully and repeatedly against a stack of lint-free absorbent towels. J2 antibody was added a concentration of to 0.5 pg/mL in a final volume of at least 10 mL. For example, 5 pL of 1 mg/mL J2 stock was added to 9.995 mL of 2% BSA in PBS. 100 pL of diluted J2 was added to every well of the ELISA plate and incubated for 1 hour at room temperature with 450 rpm shaking.

[0126] Calibration Curve: Prepare the diluent for the Calibration Curve by diluting PEG-8000 to a final concentration of 15% in 1 X PBS. For example, to prepare 6 mL of diluent, combine 1.8 mL of 50% PEG-8000, 600 pL of 10X PBS, and 3.6 mL of water. Solutions containing PEG-8000 should be mixed very thoroughly by vortexing or pipetting up and down as appropriate until no “swirliness” is apparent. The 50% PEG-8000 was observed to be very viscous and difficult to pipette. Reverse pipetting technique was used, and pipetting was done very slowly to ensure accurate quantities of 50% PEG were transferred. An intermediate stock of the calibration standard was prepared by combining the 1 mg/mL FLuc dsRNA with 50% PEG-8000 and 10X PBS and diluting the mixture to 10 pg/mL dsRNA in 15% PEG-8000 and IX PBS. The volumes of the various components of the calibration standard as provided in Table 2 below, can be scaled as needed.

Table 2. Example dilution scheme for calibration standard working stock.

[0127] It was observed that solutions containing RNA should not be vortexed, but the dsRNA standard stock solution should be thoroughly mixed. The standard stock was mixed by pipetting up and down until the PEG appears to be thoroughly diluted. The calibration standard was diluted to the highest concentration of the standard curve, 3 pg/mL dsRNA by combining 300 pL of the intermediate stock with 700 pL of 15% PEG diluent. 300 pL of the 3 pg/mL dsRNA calibration standard was added to 3 adjacent wells in column 1 of a 2 mL deep well dilution plate. 150 pL of diluent was added to the remaining wells of the dilution plate rows that received standard material. The calibration was serially diluted in 2-fold dilution steps across the dilution plate. 150 pL of material was transferred from wells in column 1 to wells in column 2 and mixed with the diluent in the recipient wells by pipetting up and down 10 times. The transfer and mixing from wells in column 2 to wells in column 3 was then repeated using fresh pipet tips. The transfer and repeats were repeated across the entire row except for column 12, which served as a blank and contained no dsRNA.

[0128] Reference Standard and Sample Preparation: For each sample or reference standard, the composition comprising mRNA drug substance was diluted 10-fold in IX PBS in a total volume of at least 1 mL. For example, 100 pL of sample was combined with 900 pL of IX PBS and mix by pipetting up and down several times. 300 pL of the diluted reference standard or sample was added to triplicate wells on the dilution plate. For example, 300 pL of diluted reference standard was added to wells DI, El, and Fl, as depicted in dilution plate layout in FIG. IB.

[0129] 150 pL of IX PBS was added to 2 sets of triplicate wells on the dilution plate for each sample or reference standard. These wells were be used for serial dilution of the reference standard or sample. For example, 150 pL of IX PBS was add to wells D2, D3, E2, E3, F2, and F3 adjacent to reference standard in wells DI, El, and Fl . The reference standard or samples from each reference standard well were diluted twice into the IX PBS of the adjacent wells by the same method as described for serial dilution of the dsRNA standard solution. Any remaining unused wells on the dilution plate were fdled with 150 pL of 10X PBS.

[0130] Plate loading: The J2 antibody solution was discarded from the ELISA plate and the plate is washed. 100 pL from each well of the dilution plate was transferred to the corresponding well of the ELISA plate. The ELISA plate was re-sealed with adhesive film and incubated at room temperature for 2 hours with 450 rpm shaking.

[0131] Detection antibodies preparation: The K2 monoclonal antibody is diluted in 2% BSA in PBS to a final volume of at least 10 mL. Typical dilution factors may range from 20-100x. The RNA samples are discarded from the ELISA plate and the plate was washed. 100 pL of diluted K2 antibody solution was added to every well of the ELISA plate. The ELISA plate was re-sealed with adhesive film and incubated at room temperature for 1 hour with 450 rpm shaking.

[0132] HRP readout antibody: The HRP -conjugated anti -mouse p-chain F(ab’)2 fragment was dilute 10,000-fold in two steps. For example, an intermediate dilution was prepared by adding 4 pL of the 1 mg/mL HRP F(ab’)2 stock to 396 pL of 2% BSA in PBS. Then, 100 pL of the intermediate dilution was combined with 9.9 mL of 2% BSA in PBS to achieve a total dilution of 10,000-fold, the K2 antibody solution was discarded from the ELISA plate and the plate was washed. 100 pL of the diluted HRP F(ab’)2 solution was added to every well of the ELISA plate. The ELISA plate was re-sealed with adhesive film and incubate at room temperature for 1 hour with 450 rpm shaking

[0133] Plate Readout: In order to carry out the TMB reaction, the HRP F(ab’)2 solution from the ELISA plate was discard and the plate was washed. 100 pL of TMB substrate solution was added to every well of the ELISA plate and wait 15 minutes. 100 pL of TMB stop solution was added to every well of the ELISA plate. Any blue TMB reaction product present in the wells immediately turned yellow.

[0134] Plate reading: The ELISA plate was loaded into the drawer of the SpectraMax M3 plate reader. Optionally the contents of the plate were mixed by using the “Shake” function for about 15 seconds. The acquisition settings were specified as per the acquisition settings described in Table 3 and data was acquired.

Table 3 SpectraMax Acquisition Settings.

[0135] Data analysis and processing: The mean A450 and % Relative Standard Deviation (%RSD) for the triplicate spots for each set of standards and samples was calculated using Microsoft Excel. The detailed steps of generating and determining the precision of a standard curve based on the concentration of dsRNA and mean A450 readings were as follows: a) the mean A450 values of the lowest 7 standards were plotted against the nominal total quantity of dsRNA in each standard; b) the standard curve was fitted with a quadratic fit and the R2 correlation coefficient was determined; c) using the parameters of the quadratic fit, the quantity of dsRNA was back- calculated in each standard based on the measured mean density; and d) the back-calculated dsRNA quantities for the lowest 7 standards was expected to be between 90-110% of the nominal value. If the fit was poor, the lowest point on the standard curve could be discarded and the previous steps of plotting, the steps a)-d), were repeated. If necessary, one outlier point on the standard curve could also be removed. The standard curve as generated using the process disclosed herein is shown in FIG. 2. 10 ⁶

[0137] Results: The mean relative dsRNA content was calculated between the 3 dilutions for each sample and the %RSD was calculated to assess dilutional linearity. For determining linearity of the standard curve, the %RSD was expected to be within <20%. The different parameters and criterion for sustainability and acceptance of the assay as described herein, were determined as in Tables 3 and 4.

Table 3. System Suitability Criteria

Table 4. Acceptance Criteria.

[0138] Conclusion: The results as described herein clearly show that the method and buffer compositions (comprising the crowding agent) of the present disclosure can be used to generate a linear standard curve and set parameters and criteria for determining the dsRNA concentration of samples. A comparison of the reproducibility and sensitivity of the ELISA based assay for determining dsRNA is described in FIG. 3 A. Additionally, the ELISA based assay disclosed herein has a high level of repeatability and diluent linearity, in terms of dilutions of dsRNA that can be detected, as compared to immunoblot assay (See FIGs. 3B). As shown in FIG. 3C, a histogram plot comparing relative level of dsRNA (bar graph) determined using the Dot Blot assay and ELISA platform based method of the present disclosure. As shown, the relative amount of dsRNA in slightly under 600 and 100 using the Dot Blot assay and ELISA platform respectively.

[0139]

Example 2: Correlation of dsRNA concentration and immunogenicity.

[0140] Objective: Described herein is a study showing the efficacy of use of the buffer compositions and ELISA based method disclosed herein, in determining the dsRNA concentration of a sample and correlation of the dsRNA concentration with immunogenicity of the sample.

[0141] Study Design and procedure: A HEK-lucia RIG-I reporter cell comprising a lucia reporter gene under control of an interferon stimulation response element (ISRE) promoter and interferon-stimulated gene, was utilized. HEK-Lucia™ RIG-I cells stably express high levels of human RIG-I (also known as Ddx58) and respond strongly to cytosolic double-stranded RNAs with an uncapped 5'-di/triphosphate end, such as 3p-hpRNA and 5’ppp-dsRNA. HEK-Lucia™ RIG-I cells were generated from HEK-Lucia™ Null cells, HEK293 -derived cells that stably express the secreted Lucia luciferase reporter gene. This reporter gene is under the control of an IFN-inducible ISG54 promoter enhanced by a multimeric IFN-stimulated response element (ISRE). Upon uptake by the reporter cell in contact with a sample, the dsRNA from a sample bind to the innate immune receptor, retinoic acid-inducible gene I (RIG-I), that activates a signaling cascade leading activation of the transcription factor IRF3/7 that induces the ISRE inducible reporter gene, Lucia leading to generation of a detectable signal (RIG-I response). The level of the detectable signal or RIG-I response generated from the reporter cell is proportional to the level of immune cell activation caused by the dsRNA in the sample when contacted with the reporter cell. The level of dsRNA in the sample was correlated with the RIG-I response to determine the immunogenic potential of the sample.

[0142] Results: A direct correlation was observed between the level of dsRNA observed in the samples and the level of detectable signal generated from the reporter cell line when contacted with the sample (FIG. 4C). Also, the level of immune activation caused by the sample was directly proportional to the ratio of high density dsRNA to low density dsRNA present in the sample (FIG. 4B). The results described herein showed that the level and content of dsRNA in a sample determined by the method disclosed herein, can determine the immunogenicity of that sample.

[0143] Based on the results described herein, the ELISA based method/platform using the buffer compositions disclosed herein, enables the use of a linear standard curve that results in more accurate and reproducible dsRNA impurity determination in samples (e.g., mRNA drug preparations) than dot blot method. Without wishing to be bound by theory, the sensitivity and accuracy of dsRNA detection and possibly formation may be dependent on the ELISA matrix conditions including salt and local crowding interactions.

Example 3: Enzyme-linked immunodetection assay (ELISA) for detection and quantification of dsRNA using KI capture antibody and K2 detection antibody and Ficoll® as crowding agent. [0144] Objective: The study described herein describes evaluation of an ELISA platform using two monoclonal antibodies, KI and K2, and Ficoll® as crowding agent, for detection of dsRNA.

[0145] Study Design and procedure: The dsRNA present in a sample containing the mRNA drug substance is captured and detected in a sandwich ELISA format using two monoclonal antibodies, KI (capture antibody) and K2 (detection antibody), that both bind specifically to dsRNA. Briefly, an ELISA plate was first coated with Protein A, which was then loaded with the KI antibody at a dilution of 1:2000, for analyte capture. After RNA samples were allowed to interact with the bound KI antibody, the K2 antibody was then added at a dilution of 1:50, for detection. To read out the signal, an HRP enzyme-conjugated F(ab’)2 fragment that specifically targets the p-chain of IgM immunoglobulins was added to the ELISA plate. Quantification was achieved by addition of the chromogenic HRP substrate TMB, which can be detected by the absorbance of 450 nm light. All samples comprising mRNA drug substance spiked with dilutions of known amounts of dsRNA or reference standards comprising known amount of dsRNA, contained 10% Ficoll® as crowding agent.

[0146] Results: The mean A450 and % Relative Standard Deviation (%RSD) for the triplicate spots for each set of six standards and two dsRNA spiked samples containing mRNA drug substance, was calculated, as described in Example 1. The standard curve as generated using the process disclosed herein is shown in FIG. 5. The mean relative dsRNA content was calculated between the 3 dilutions for each sample and the %RSD was calculated, as described in Example 1 (Table 5). A dsRNA recovery rate of 87% and 101% was determined for the 1 :20 and 1 :40 dsRNA spiked mRNA drug substance samples, respectively.

[0147]

Table 5: ELISA data of dsRNA spiked samples using K2 capture antibody, KI detection antibody and Ficoll® as crowding agent.

INCORPORATION BY REFERENCE

[0148] The entire disclosure of each of the patent documents and scientific articles referred to herein is incorporated by reference for all purposes.

EQUIVALENTS

[0149] The disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting the disclosure described herein. Various structural elements of the different embodiments and various disclosed method steps may be utilized in various combinations and permutations, and all such variants are to be considered forms of the disclosure. Scope of the disclosure is thus indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein. [0150] The disclosure herein is embodied in the non-limiting enumerated clauses as described herein:

1. A method of quantitatively measuring an amount of double-stranded RNA (dsRNA) present in a sample solution, the method comprising: a. contacting the sample solution with a dsRNA capture reagent and a dsRNA detection reagent, and detecting a signal from the dsRNA detection reagent in the sample solution; b. calculating a dsRNA detection reagent signal using the signal from the dsRNA detection reagent in the sample solution; c. contacting dilutions of a dsRNA standard solution with a dsRNA capture reagent and a dsRNA detection reagent, and detecting a signal from the dsRNA detection reagent in each dilution of the dsRNA standard solution; d. generating a calibration curve using the signal from the dsRNA detection reagent at each dilution of the dsRNA standard solution; and e. comparing the dsRNA detection reagent signal with the calibration curve to quantitatively determine the concentration of dsRNA in the sample solution; wherein the dsRNA standard solution comprises a molecular crowding agent; and the dilutions of the dsRNA standard solution comprise from about 0.0001 pg/ml dsRNA to about 5 pg/ml dsRNA.

2. The method of clause 1, wherein the molecular crowding agent comprises a doublestranded conformation-stabilizing polymer.

3. The method of clause 1 or 2, wherein the molecular crowding agent comprises a polyethylene glycol (PEG), a dextran, or a Ficoll " .

4. The method of any one of clauses 1-3, wherein the molecular crowding agent is present at a concentration effective to stabilize a double-stranded conformation of the dsRNA polynucleotides.

5. The method of any one of clauses 1-4, wherein the molecular crowding agent is PEG- 8000.

6. The method of clause 5, wherein the PEG-8000 is present in the dsRNA standard solution at a concentration of about 0.01% v/v to about 50% v/v before dilution. The method of clause 6, wherein the PEG-8000 is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 15% v/v before dilution. The method of any one of clauses 1-4, wherein the molecular crowding agent is a dextran. The method of clause 8, wherein the dextran is present in the dsRNA standard solution at a concentration of about 0.01% v/v to about 50% v/v before dilution. The method of any one of clauses 8 or 9, wherein the dilutions of the dsRNA standard solution comprise the dextran at a concentration of about 0.1% v/v to about 25% v/v before dilution. The method of any one of clauses 1-4, wherein the molecular crowding agent is a Ficoll. The method of clause 11, wherein the Ficoll is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 50% v/v before dilution before dilution. The method of any one of clauses 11 or 12, wherein the dilutions of the dsRNA standard solution comprise the Ficoll at a concentration of about 0.1% v/v to about 10% v/v before dilution. The method any one of clauses 1-13, wherein the method comprises an ELISA assay. The method any one of clauses 1-14, wherein the method comprises a sandwich ELISA assay. The method of any one of clauses 1-15, wherein the dsRNA capture reagent is immobilized on a solid substrate. The method of any one of clauses 1-16, wherein the dsRNA capture reagent is an antibody or fragment thereof that specifically binds dsRNA. The method of any one of clauses 16 or 17, wherein the dsRNA capture reagent is bound to Protein A immobilized on the solid substrate. The method of any one of clauses 1-18, wherein the dsRNA detection reagent is an antibody or fragment thereof that specifically binds dsRNA. The method of any one of clauses 1-19, wherein the dsRNA capture reagent is J2 antibody or an antigen-binding fragment thereof. The method of clause 20, wherein the dsRNA detection reagent is K2 antibody or an antigen-binding fragment thereof. The method of any one of clauses 1-19, wherein the dsRNA capture reagent is K2 antibody or an antigen-binding fragment thereof. The method of clause 22, wherein the dsRNA detection reagent is J2 antibody or an antigen-binding fragment thereof. The method of any one of clauses 1-19, wherein the dsRNA capture reagent is J2 IgG isotype antibody, or an antigen-binding fragment thereof bound to Protein A immobilized on the solid substrate. The method of clause 24, wherein the concentration of the dsRNA capture reagent is about 0.1 mg/ml to about 1.0 mg/ml. The method of clause 25, wherein the concentration of the dsRNA capture reagent is about 0.5 mg/ml. The method of any one of clauses 24-26, wherein the dsRNA detection reagent is an IgM isotype antibody or fragment thereof that specifically binds dsRNA and does not specifically bind Protein A. The method of clause 27, wherein the dsRNA detection reagent is K2 IgM isotype antibody or antigen-binding fragment thereof. The method of clause 28, wherein the dsRNA detection reagent is used at a dilution of about 1:20 to about 1 :100. The method of clause 29, wherein the dsRNA detection reagent is used at a dilution of about 1 : 100. The method of any one of clauses 1-30, wherein detecting a signal from the dsRNA detection reagent comprises contacting the detection reagent with a secondary detection reagent. The method of clause 31, wherein the secondary detection reagent is an antibody or fragment thereof that specifically binds the dsRNA detection reagent. The method of any one of clauses 31 or 32, wherein the secondary detection reagent comprises a reporter moiety. The method of clause 33, wherein the reporter moiety is a chromogenic enzyme. The method of clause 34, wherein the reporter moiety is horse radish peroxidase (HRP). The method of any one of clauses 31-35, wherein the secondary detection reagent is an HRP -conjugated anti-mouse p-chain F(ab’)2 fragment. The method of any one of clauses 1-36, wherein the dsRNA standard solution comprises dsRNA polynucleotides of one or more defined lengths in base pairs (bp). The method of clause 37, wherein the dsRNA polynucleotides comprise one or more defined lengths of about 50 bp to about 10,000 bp. The method of any one of clauses 37 or 38, wherein the one or more defined lengths are in increments of about 5 bp, increments of about 10 bp, increments of about 20 bp, increments of about 50 bp, increments of about 100 bp, and/or increments of about 1,000 bp. The method of any one of clauses 37-39, wherein the dsRNA polynucleotides are of one or more defined lengths selected from one or more of about 50 bp, about 60 bp, about 70 bp, about 80 bp, about 90 bp, about 100 bp, about 150 bp, about 200 bp, about 250 bp, about 300 bp, about 350 bp, about 400 bp, about 450 bp, about 500 bp, about 550 bp, about 600 bp, about 650 bp, about 700 bp, about 750 bp, about 800 bp, about 850 bp, about 900 bp, about 950 bp, about 1,000 bp, about 1,100 bp, about 1,200 bp, about 1,300 bp, about 1,400 bp, about 1,500 bp, about 1,600 bp, about 1,700 bp, about 1,800 bp, about 1,900 bp, about 2,000 bp, about 2,100 bp, about 2,200 bp, about 2,300 bp, about 2400 bp, about 2,500 bp, about 2,600 bp, about 2,700 bp, about 2,800 bp, about 2,900 bp, about 3,000 bp, about 3,100 bp, about 3,200 bp, about 3,300 bp, about 3,400 bp, about 3,500 bp, about 3,600 bp, about 3,700 bp, about 3,800 bp, about 3,900 bp, about 4,000 bp, about 41,00 bp, about 4,200 bp, about 4,300 bp, about 4,400 bp, about 4,500 bp, about 4,600 bp, about 4,700 bp, about 4,800 bp, about 4,900 bp, about 5,000 bp, about 5,100 bp, about 5,200 bp, about 5,300 bp, about 5,400 bp, about 5,500 bp, about 5,600 bp, about 5,700 bp, about 5,800 bp, about 5,900 bp, about 6,000 bp, about 6,100 bp, about 6,200 bp, about 6,300 bp, about 6,400 bp, about 6,500 bp, about 6,600 bp, about 6,700 bp, about 6,800 bp, about 6,900 bp, about 7,000 bp, about 7,100 bp, about 7,200 bp, about 7,300 bp, about 7,400 bp, about 7,500 bp, about 7,600 bp, about 7,700 bp, about 7,800 bp, about 7,900 bp, about 8,000 bp, about 8,100 bp, about 8,200 bp, about 8,300 bp, about 8,400 bp, about 8,500 bp, about 8,600 bp, about 8,700 bp, about 8,800 bp, about 8,900 bp, about 9,000 bp, about 9,100 bp, about 9,200 bp, about 9,300 bp, about 9,400 bp, about 9,500 bp, about 9,600 bp, about 9,700 bp, about 9,800 bp, about 9,900 bp, and about 10,000 bp. The method of any one of clauses 37-40, wherein the dsRNA polynucleotides are of one or more defined lengths of about 100 bp to about 500 bp. The method of any one of clauses 37-41, wherein the dsRNA polynucleotides are of a defined length of about 200 bp to about 400 bp. The method of clause 42, wherein the dsRNA polynucleotides are of a defined length of about 355 bp. The method of any one of clauses 37-43, wherein the dsRNA polynucleotides are derived from a reporter gene. The method of any one of clauses 37-44, wherein the dsRNA polynucleotides are derived from a firefly luciferase reporter gene. The method of any one of clauses 37-45, wherein dsRNA standard solution comprises the dsRNA polynucleotides at a starting concentration of about 1 mg/ml before dilution. The method of any one of clauses 37-46, wherein the dsRNA standard solution comprises firefly luciferase dsRNA at a concentration of about 1 mg/ml before dilution. The method of any one of clauses 1-47, wherein steps a. and c. further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent for a period of about 1-4 hours. The method of any one of clauses 1-48, wherein steps a. and c. further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA detection reagent for a period of about 1-3 hours. The method of any one of clauses 1-49, wherein steps a. and c. further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA capture reagent for a period of about 1-3 hours. The method of any one of clauses 1-50, wherein steps a. and c. further comprise incubating the sample solution and dilutions of the standard solution, respectively, with the dsRNA detection reagent for a period of about 1-2 hours. A composition for use as a dsRNA standard solution, the composition comprising dsRNA polynucleotides of one or more defined lengths in base pairs (bp) and a molecular crowding agent. The composition of clause 52, wherein the molecular crowding agent comprises a double-stranded conformation-stabilizing polymer. The composition of clause any one of clauses 52 or 53, wherein the molecular crowding agent comprises a polyethylene glycol (PEG), a dextran, or a Ficoll®. The composition of any one of clauses 52-54, wherein the molecular crowding agent is present at a concentration effective to stabilize a double-stranded conformation of the dsRNA polynucleotides. The composition of any one of clauses 52-55, wherein the molecular crowding agent comprises a PEG. The composition of any one of clauses 52-56, wherein the molecular crowding agent is PEG-8000. The composition of clause 57, wherein the PEG-8000 is present in the dsRNA standard solution at a concentration of about 0.01% v/v to about 50% v/v before dilution. The composition of clause 58, wherein the PEG-8000 is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 15% v/v before dilution. The composition of any one of clauses 52-55, wherein the molecular crowding agent is a dextran. The composition of clause 60, wherein the dextran is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 25% v/v before dilution. The composition of any one of clauses 52-55, wherein the molecular crowding agent is a Ficoll®. The composition of clause 62, wherein the Ficoll ' is present in the dsRNA standard solution at a concentration of about 0.1% v/v to about 50% v/v before dilution. The composition of any one of clauses 52-63, wherein the dsRNA polynucleotides comprise one or more defined lengths of about 50 bp to about 10,000 bp. The composition of any one of clauses 52-64, wherein the one or more defined lengths are in increments of about 10 bp, increments of about 20 bp, increments of about 50 bp, increments of about 100 bp, and/or increments of about 1,000 bp. The composition of any one of clauses 52-65, wherein the dsRNA polynucleotides are of one or more defined lengths selected from one or more of about 50 bp, about 60 bp, about 70 bp, about 80 bp, about 90 bp, about 100 bp, about 150 bp, about 200 bp, about 250 bp, about 300 bp, about 350 bp, about 400 bp, about 450 bp, about 500 bp, about 550 bp, about 600 bp, about 650 bp, about 700 bp, about 750 bp, about 800 bp, about 850 bp, about 900 bp, about 950 bp, about 1,000 bp, about 1,100 bp, about 1,200 bp, about 1,300 bp, about 1,400 bp, about 1,500 bp, about 1,600 bp, about 1,700 bp, about 1,800 bp, about 1,900 bp, about 2,000 bp, about 2,100 bp, about 2,200 bp, about 2,300 bp, about 2400 bp, about 2,500 bp, about 2,600 bp, about 2,700 bp, about 2,800 bp, about 2,900 bp, about 3,000 bp, about 3,100 bp, about 3,200 bp, about 3,300 bp, about 3,400 bp, about 3,500 bp, about 3,600 bp, about 3,700 bp, about 3,800 bp, about 3,900 bp, about 4,000 bp, about 41,00 bp, about 4,200 bp, about 4,300 bp, about 4,400 bp, about 4,500 bp, about 4,600 bp, about 4,700 bp, about 4,800 bp, about 4,900 bp, about 5,000 bp, about 5,100 bp, about 5,200 bp, about 5,300 bp, about 5,400 bp, about 5,500 bp, about 5,600 bp, about 5,700 bp, about 5,800 bp, about 5,900 bp, about 6,000 bp, about 6,100 bp, about 6,200 bp, about 6,300 bp, about 6,400 bp, about 6,500 bp, about 6,600 bp, about 6,700 bp, about 6,800 bp, about 6,900 bp, about 7,000 bp, about 7,100 bp, about 7,200 bp, about 7,300 bp, about 7,400 bp, about 7,500 bp, about 7,600 bp, about 7,700 bp, about 7,800 bp, about 7,900 bp, about 8,000 bp, about 8,100 bp, about 8,200 bp, about

8,300 bp, about 8,400 bp, about 8,500 bp, about 8,600 bp, about 8,700 bp, about 8,800 bp, about 8,900 bp, about 9,000 bp, about 9,100 bp, about 9,200 bp, about 9,300 bp, about 9,400 bp, about 9,500 bp, about 9,600 bp, about 9,700 bp, about 9,800 bp, about

9,900 bp, and about 10,000 bp. The composition of any one of clauses 52-66, wherein the dsRNA polynucleotides are of one or more defined lengths of about 100 bp to about 500 bp. The composition of any one of clauses 52-67, wherein the dsRNA polynucleotides are of a defined length of about 200 bp to about 400 bp. The composition of clause 68, wherein the dsRNA polynucleotides are of a defined length of about 355 bp. The composition of any one of clauses 52-69, wherein the dsRNA polynucleotides are derived from a reporter gene. The composition of any one of clauses 52-70, wherein the dsRNA polynucleotides are derived from a firefly luciferase reporter gene. The composition of any one of clauses 52-71, wherein dsRNA standard solution comprises the dsRNA polynucleotides at a starting concentration of about 1 mg/ml before dilution. The composition of any one of clauses 52-72, wherein the dsRNA standard solution comprises firefly luciferase dsRNA at a concentration of about 1 mg/ml before dilution. A kit for quantitative measurement of dsRNA present in a sample solution, the kit comprising: a. a dsRNA standard solution comprising dsRNA polynucleotides and a molecular crowding agent of the composition of any one of clauses 52-73; and b. one or more reagents for carrying out an assay for detecting dsRNA present in a sample solution. The kit of clause 74, wherein the assay is an ELISA assay. The kit of clause 75, wherein the assay is a sandwich ELISA assay. A method of screening a set of procedures for reducing dsRNA content of a sample solution comprising a known amount of dsRNA, the method comprising: a. performing each of the set of procedures on an amount of the sample solution for an amount of time to form a set of test sample solutions, the amount of sample solution and amount of time being same for each compound of the set; b. quantifying the amount of dsRNA in each test sample solution using the method of any one of clauses 1-51; and c. determining if a procedure of the set is effective in reducing dsRNA from the sample if the concentration of dsRNA in the corresponding test sample solution is reduced by at least 90%, as compared to the sample solution before contacting with the compound. The method of clause 77, wherein one or more of the procedures of reducing dsRNA content of a sample solution of the set comprises: a. contacting an amount of the sample solution with a compound; b. maintaining an amount of the sample solution under a condition; c. contacting an amount of the sample solution with an affinity chromatography medium; or d. passing an amount of the sample solution through a filtration medium. A method of correlating an amount of dsRNA in a sample solution with immunogenicity of the sample solution, the method comprising: a. quantitatively measuring the amount of dsRNA present in the sample dilutions according to any one of clauses 1-51; b. quantitatively measuring the level of immune activation induced by the sample by conducting an in vitro immune activation assay using the sample; and c. determining the amount of dsRNA to be non-immunogenic if the corresponding level of immune activation induced by the sample as determined in (b) is less than or equal to a pre-determined value. The method of clause 79, wherein the in vitro immune activation assay is an in vitro innate immune receptor pathway activation assay. The method of clause 80, wherein the in vitro immune activation assay is selected from any one of a RIG-1 activation assay, an MDA-5 activation assay and a TLR-3 activation assay.