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Title:
CARTRIDGE GEL ELECTROPHORESIS DEVICE FOR SEPARATING BIOMOLECULES
Document Type and Number:
WIPO Patent Application WO/2023/019105
Kind Code:
A1
Abstract:
A gel electrophoresis cartridge and console are disclosed for use in performing electrophoretic separations. The cartridge includes at least one separation column comprising a cathode chamber, sample introduction chamber, separation lane, and anode chamber, which is filled with electrophoresis separation gel by the user using a passive, pumpless surface wetting method. The sample introduction chamber within the separation lane contains either geometric modifications or hydrophobic treatment of the walls to prevent the filling with gel, leaving an empty chamber suitable for introduction of a biological sample. Gel within the filled cartridge makes contact with an anode and cathode without buffers or liquid overlay, resulting in an improved bufferless electrophoresis cartridge. An electrophoresis console can be used for the application of separation voltage to the cartridge, as well as for real-time monitoring of the progress of the electrophoretic separation.

Inventors:
MCCLURE MARK DONALD (US)
Application Number:
PCT/US2022/074661
Publication Date:
February 16, 2023
Filing Date:
August 08, 2022
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
KEYDEV INC (US)
International Classes:
G01N27/447; G01N30/88
Domestic Patent References:
WO2009108260A22009-09-03
WO2008124064A12008-10-16
WO2012168737A12012-12-13
WO2007082480A12007-07-26
WO2016205428A12016-12-22
Foreign References:
US3715295A1973-02-06
US5582702A1996-12-10
US6905585B22005-06-14
US7208072B22007-04-24
Other References:
KASICKA VÁCLAV: "Recent advances in capillary electrophoresis and capillary electrochromatography of peptides", ELECTROPHORESIS, vol. 24, no. 2223, 2 December 2003 (2003-12-02), Hoboken, USA, pages 4013 - 4046, XP055861944, ISSN: 0173-0835, DOI: 10.1002/elps.200305660
ANONYMOUS: "Capillary electrophoresis - Wikipedia", 22 July 2021 (2021-07-22), XP055982446, Retrieved from the Internet [retrieved on 20221117]
WANG: "A Review of Capillary Control Valves in Microfluidics", BIOSENSORS, vol. 11, 2021, pages 405
Attorney, Agent or Firm:
GUNNERSON, Gregory Lars et al. (US)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A cartridge device (101/201) with at least one separation column (109) comprising: a separation lane (102) having a first and second end; a cathode chamber (105) at the first end of the separation lane (102); an anode chamber (106) at the second end of the separation lane (102); a sample input chamber (104) within the separation lane (102); capillary valves that define boundaries of the sample input chamber (104) within the separation lane (102); an opening in the sample input chamber (104) perpendicular to the capillary valves; wherein a volume of said separation lane (102) is equal to or less than the volume of the cathode chamber (105).

2. The cartridge device (101/201) according to claim 1 wherein the cathode chamber (105) and anode chamber (106) are filled with fluid separation gel.

3. The cartridge device (101/201) according to any one of claims 1-2 wherein fluid separation gel from the anode chamber (106) and cathode chamber (105) subsequently migrates and fills the separation lane (102) by surface wetting.

4. The cartridge device (101/201) according to any one of claims 1-3 wherein the migration and filling of the separation lane (102) with the fluid gel stops at the capillary valves, leaving an empty volume within the sample input chamber (104).

5. The cartridge device (101/201) according to any one of claims 2-4 wherein the only buffering material within the cartridge device (101) is separation gel.

6. The cartridge device (101/201) according to any one of claims 1-5, wherein the sample input chamber (104) is located closer to the cathode chamber (105) than the anode chamber (106).

7. The cartridge device (101/201) according to any one of claims 1-6 wherein the sample input chamber (104) is located between 1 percent and 33 percent of the length of the separation lane (102) from the first end.

8. The cartridge device (101/201) according to any one of claims 1-7 wherein the capillary valves comprise an increase in the width of the separation lane (102).

9. The cartridge device (101/201) according to any one of claims 1-8 wherein the capillary valves comprise a decrease in the width of the separation lane (102).

10. The cartridge device (101/201) according to any one of claims 1-9 wherein the capillary valves incorporate a sharp ledge (302/303).

11. The cartridge device (101/201) according to any one of claims 1-10 wherein the capillary valves comprise a hydrophobic modification of walls of the sample input chamber (104).

12. The cartridge device (101/201) according to any one of claims 1-11 wherein the dimensions of said separation lane (102) are 0.2 mm to 6.5 mm width, 0.2 mm to 6.5 mm depth, and 20 mm to 250 mm long.

13. The cartridge device (101/201) according to any one of claims 1-12 wherein the volume of said separation lane (102) is equal to or less than the volume of the anode chamber (106).

14. The cartridge device (101/201) according to any one of claims 1-13 wherein a cross sectional area of the separation lane (102) is at least 1 cubic millimeter for the entire length of the separation lane (102).

15. The cartridge device (101/201) according to any one of claims 1-14 wherein a cross sectional area of the separation lane (102) is at least 0.5 cubic millimeters for the entire length of the separation lane (102).

16. The cartridge device (101/201) according to any one of claims 1-15 wherein a cross sectional area of the separation lane is at least 0.25 cubic millimeters for the entire length of the separation lane (102).

17. The cartridge device (101/201) according to any one of claims 1-16 wherein the separation lane (102) is substantially enclosed air and liquid tight. 17

18. The cartridge device (101/201) according to any one of claims 1-17 wherein the separation lane (102) is substantially rectangular.

19. The cartridge device (101/201) according to any one of claims 1-18 wherein the cartridge device (101/201) is constructed of an upper clear polymer substrate (203, 204) and a lower 3- dimensionally molded polymer substrate (205); wherein the lower and upper substrates (203, 204, 205) are attached to form a liquid tight interface.

20. The cartridge device (101/201) according to claim 19 wherein the upper clear polymer substrate (203, 204) comprises a clear plastic thin film cover (203) severed into two pieces by an elongated opening (202) traversing the entire width of the clear plastic thin film cover.

21. The cartridge device (101/201) according to claim 20 wherein the elongated opening (202) in the upper clear polymer substrate (203) allows sample placement through the opening in the sample input chamber (104).

22. The cartridge device (101/201) according to any one of claims 19-21 wherein the cartridge device (101/201) comprises a plurality of separation columns (109) and further wherein the opening (202/209) in the upper clear polymer substrate (203/204) allows sample placement through the opening in the sample input chamber of each and every separation column.

23. The cartridge device (101/201) according to any one of claims 1-19 wherein the cartridge device (101/201) comprises a plurality of separation columns (109).

24. The cartridge device (101/201) according to claim 23 wherein the anode chambers are fluidly connected.

25. The cartridge device (101/201) according to any one of claims 23-24 wherein the cathode chambers are fluidly connected.

26. The cartridge device (101/201) according to any one of claims 23-25 wherein the upper clear polymer substrate (203, 204) comprises a clear plastic thin film cover (204) that has a plurality of slits (209) that correspond to and allow sample placement through each opening in the sample input chamber (104) of the plurality of separation columns (109). 18

27. The cartridge device (101/201) according to claim 26 wherein the clear plastic thin film cover (204) further comprises vents (207, 210).

28. The cartridge device (101/201) according to any one of claims 26-27 wherein the clear plastic thin film cover (204) further comprises contains holes 208 for input of gel electrophoresis matrix (503) into the anode chamber (106) and the cathode chamber (105).

29. The cartridge device (201) according to any one of claims 1-28 wherein the cartridge device (101) is molded using a thermoforming.

30. The cartridge device (101/201) according to any one of claims 1-29 further comprising a label (103) for displaying identifying information.

31. The cartridge device (101/201) according to any one of claims 1-30 further comprising a conductive strip (107) contacting the anode chamber (106).

32. The cartridge device (101/201) according to claim 31 further comprising a conductive strip (108) contacting the cathode chamber (105).

33. The cartridge device (101/201) according to claim 32 wherein the conductive strips (107, 108) comprise an indentation (206).

34. The cartridge device (101/201) according to any one of claims 1-33 further comprising an indentation (302/303/307) in the sample input chamber (104).

35. The cartridge device (101/201) according to any one of claims 1-34, wherein the cathode (108) has a negative charge applied and the anode (107) has a positive charge applied.

36. The cartridge device (101/201) according to any one of claims 1-35, wherein the polarity is reversed, and the anode (107) has a negative charge applied and the cathode (108) has a positive charge applied.

37. An electrophoresis console (601) comprising the cartridge device according to any one of claims 1-34. 19

38. The electrophoresis console (601) according to claim 37 further comprising an LED light (602) that turns color for a timed “electrophoresis on” state.

39. The electrophoresis console (601) according to claim 38 wherein no light indicates an “electrophoresis off’ state.

40. The electrophoresis console (601) according to any one of claims 38-39 further comprising a semi-transparent emission filter (604) that removes excitation wavelength light but allows other light to pass, thereby enabling a user to view electrophoresis separation real time during the electrophoretic separation.

41. The electrophoresis console (601) according to claim 40 wherein the semi-transparent emission filter (604) further comprises magnets (605) that can magnetically attach to magnets (607) located on an enclosure (611) of the electrophoresis console (601).

42. The electrophoresis console (601) according to any one of claims 40-41 further comprising holes placed into the emission filter (604) to allow air flow from fans (609) up and around an excitation filter (608).

43. The electrophoresis console (601) according to any one of claims 39-42 further comprising at least 1 fan (609) to provide air flow to cool heat generated by the control board (613), LED light array (616), and the cartridge device (101/201).

44. The electrophoresis console (601) according to claim 43 wherein the control board (613) carries a high voltage power supply, LED driver, microprocessor, and voltage regulation circuitry.

45. The electrophoresis console (601) according to any one of claims 43-44 wherein the excitation filter (608) allows the excitation wavelengths of interest to pass from the LED array (616) so that the electrophoresis device (101/201) is illuminated during electrophoresis.

46. The electrophoresis console (601) according to any one of claims 43-45 further comprising a top cover (612) that covers the control board (613) and a chassis frame (618). 20

47. The electrophoresis console (601) according to any one of claims 37-46 further comprising a camera attachment hood (702) that attaches to the electrophoresis console (601).

48. A separation column (109) comprising: a channel (102) having an anode (107) positioned near a first end and a cathode (108) positioned near a second end, wherein the first end and the second end are located at opposite sides of the separation lane (102); a sample input chamber (104) placed between the anode (107) and the cathode (108); a separation electrophoresis gel fluidly connecting sample input chamber (104) to the anode (107) and the cathode (108); and physical boundaries capable of stopping the advancement of a flow of liquid from - entering the sample input chamber (104); wherein a sample can be placed through an opening into the separation column (109).

Description:
TITLE: CARTRIDGE GEL ELECTROPHORESIS DEVICE FOR SEPARATING

BIOMOLECULES

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. § 119 to provisional patent application U.S. Serial No. 63/230,788, titled “Hybrid Midifluidic Device Incorporating Microfluidics and Slab Gel Electrophoresis”, filed August 08, 2021. The provisional patent application is herein incorporated by reference in its entirety, including without limitation, the specification, claims, and abstract, as well as any figures, tables, appendices, or drawings thereof.

TECHNICAL FIELD

[0002] The present disclosure relates to a gel cartridge, system, and method for conducting electrophoresis tests.

BACKGROUND

[0003] The background description provided herein gives context for the present disclosure. Work of the presently named inventors, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art.

[0004] Slab gel electrophoresis is used to separate molecules based on size, shape, and charge. Traditional slab gel electrophoresis is a time and labor intensive process requiring careful skill, taking approximately 1 to 8 (or more) hours to prepare and run.

[0005] Pre-manufactured gel cartridges solve some of the labor issues by shifting the gel preparation steps to the factory. Examples are discussed in United States Patent Nos. 3,715,295 to Tocci, 5,582,702 to Cabilly et. al., and 6,905,585 to Goncalves. Customers purchase a pre-cast gel, which eliminates the lengthy preparation steps. However, these systems have not gained widespread popularity because cartridges a) are many times the cost cost of traditional slab gels, b) have a limited shelf life of typically less than 6 months, c) require all lanes within a cartridge be run at once, even if only one lane is desired d) often require flushing, preruns, and buffer overlays, e) create large amounts of chemical and plastics waste, f) require special versions for sample recovery, g) require a buffer solution separate from the separation gel, and h) lack the ability of users to apply their own custom gels.

[0006] Other solutions to the time and effort associated with slab gel electrophoresis are accomplished through automated capillary and microfluidic systems, examples of which are described in United States Patent No. 7,208,072 to Amirkhanian et. al. and 6,316,201 to Nikiforov. Although these systems offer greatly enhanced resolution and speed compared to traditional slab gel electrophoresis, they have issues, including a) the systems are expensive, precluding many labs from access b) they typically require multiple samples/lanes to be run at once c) they lack the ability of users to apply their own custom gels, d) excision or capture of separated samples is typically not possible, e) the cartridges/sy stems require a buffer solution separate from the separation gel, and f) the systems require careful and costly maintenance.

[0007] Thus, there exists a need for a slab-gel electrophoresis technology that a) requires 5 minute or less setup time, b) can be manufactured and sold at a competitive cost to slab gel electrophoresis, c) allows only lanes of interest to be run/analyzed c) has no shelf life limitation, d) has fast 3-7 minute runtimes, e) requires no messy cleanup, f) has no separate liquid buffer, overlays, or liquid buffer reservoir g) allows separated sample to be easily excised and recovered f) is easy to transport, g) uses low amounts of reagent inputs and h) allows the practitioner to use their own gel, either a commercial solid or gel matrix known in the art (such as agarose of polyacrylamide), or custom specialty gels designed and used by the practitioner for their specific application.

SUMMARY

[0008] The following objects, features, advantages, aspects, and/or embodiments, are not exhaustive and do not limit the overall disclosure. No single embodiment need provide each and every object, feature, or advantage. Any of the objects, features, advantages, aspects, and/or embodiments disclosed herein can be integrated with one another, either in full or in part.

[0009] It is a primary object, feature, and/or advantage of the present disclosure to improve on or overcome the deficiencies in the art.

[0010] A multi-lane gel cartridge with a console system for improved handling, reduced cost, and faster results in the electrophoresis and separation of biomolecules using gel electrophoresis is shown and described herein.

[0011] One aspect, object, feature, and/or advantage of the present disclosure is a gel cartridge with at least one separation column comprising a cathode chamber, a sample input chamber, a separation lane, and an anode chamber. The cartridge is designed so that when a molten or liquid separation gel is placed into the anode chamber and cathode chamber, surface wetting causes the molten or liquid gel to fill the separation lane up to the sample input chamber boundary. The cartridge contains either geometric modifications or surface hydrophobic modifications that inhibit gel from migrating into and filling the sample input chamber. No gravity, pump pressure, pipette pressure, or vacuum pressure is required to fill the separation lane. This allows the user to easily fill the gel cartridge by pipetting a few drops of molten or liquid gel into the anode and cathode chamber without any additional pumping, vortexing, centrifugation, or vacuum application steps to assist in the filling of the separation lane and anode/cathode chambers.

[0012] Another aspect, object, feature, and/or advantage of the present disclosure is a small total void volume of cathode chamber, anode chamber and separation lane. For example, the total volume can be between 0.25 mL to 2 mL. This allows the user to apply only a small amount of gel per separation, resulting in vastly improved cost savings per run. The small volume also allows molten separation media, such as agarose gel, to rapidly cool and solidify, resulting in short (less than 5 minutes) overall cartridge preparation time, allowing the users to have a complete preparation and separation time of less than 10 minutes.

[0013] Another aspect, object, feature, and/or advantage of the present disclosure is the inclusion of 3-dimensional features into the cartridge that prevent the migration of gel via surface wetting forces into the sample input chamber. This allows the user to fill the separation lane by placing a few drops of molten or liquid gel into the anode chamber and cathode chamber. The sample input chamber remains empty and gel-free, allowing for subsequent input of the sample for analysis.

[0014] Another aspect, object, feature, and/or advantage of the present disclosure is a hydrophobic modification of the surfaces of the plastic walls of the sample input chamber, which inhibits the migration of gel via surface wetting forces into the sample input chamber. This allows the user to fill the separation lane by placing a few drops of molten or liquid gel into the anode chamber and cathode chamber. The sample input chamber remains empty and gel-free, allowing for subsequent input of the sample for analysis.

[0015] Another aspect, object, feature, and/or advantage of the present disclosure is the use of low-cost materials such as thermoplastic films, designed for high-speed, high-volume construction, allowing a low cost of the final cartridge. This, coupled with the low volume of consumables such as gel, allows for a system that is lower in cost than the current traditional gel electrophoresis.

[0016] Another aspect, object, feature, and/or advantage of the present disclosure has an anode chamber and cathode chamber that when placed in a vertical position are higher than the separation lane. This allows for a passive, gravity-assist filling of the separation lane when liquid gel is placed into the anode and cathode chambers.

[0017] Another aspect, obj ect, feature, and/or advantage of the present disclosure is a gel cartridge that allows the user to apply their own gel for the separation and analysis of biomolecules. Either commercial or custom gels (i.e. with the addition of surfactants, denaturants, dyes, etc.) can be used. Thus, users are not tethered to the manufacturer’s choice of gel.

[0018] Another aspect, object, feature, and/or advantage of the present disclosure is an improved bufferless gel electrophoresis system. The reagents used to fill the cartridge are electrophoresis separation gel only, as well as the input sample for separation. There is no liquid water overlay, liquid buffer overlay, or liquid buffer reservoir. Bufferless operation is achieved by (a) sizing electrode chamber volumes to provide sufficient buffering (i.e., for ions and pH) relative to the separation channel volume (c) sizing electrode chamber surface area for sufficient heat dissipation d) sizing the separation channels to have a small cross sectional area (e.g. , 2.25 square millimeters) to allow for less electrical power usage and less heat buildup (e) enclosing the separation channel to limit evaporation of the buffer in the gel.

[0019] For improved resolution, the separation channel is split into non-continuous segments of gel at the sample loading chamber. This allows the sample to be the only material to form the electrical path between the gel segments in the separation channel, resulting in a more consistent electrical field across the sample with sharper separation bands with minimal smearing or smiling. Contrasted with prior art, previous methods cast a sample well using the gel to contain the sample. [0020] Another aspect, object, feature, and/or advantage of the present disclosure is a cartridge design with a thin plastic film construction of approximately 20 microns to 400 microns that allows users to easily excise a specific portion of gel after the electrophoresis is complete. This allows users to obtain purified samples for downstream use.

[0021] Another aspect, object, feature, and/or advantage of the present disclosure is a console that allows users to run the electrophoresis of the prepared gel cartridge, as well as to analyze and visualize the electrophoresis as it occurs, in real time using a fluorescent imaging system.

[0022] Another aspect, object, feature, and/or advantage of the present disclosure is a process for analyzing biomolecules using the gel cartridge and analysis console. The steps comprise (a) melting a small amount of gel (preferably between 0.5 and 2.0 mL), (b) placing the gel cartridge into the analysis console, (c) placing a few drops of molten gel into the anode chamber and cathode chamber, and allowing the gel to migrate into the separation lane up to the boundaries of the sample input chamber, (d) allowing the gel to solidify (typically 3-5 minutes), (e) placing between 0.5-100 pL of sample into the sample input chamber, (f) applying a voltage for desired time (typically < 5 minutes), (g) viewing and recording the results, and h) excising a sample from the cartridge, if desired.

[0023] These and/or other objects, features, advantages, aspects, and/or embodiments will become apparent to those skilled in the art after reviewing the following brief and detailed descriptions of the drawings. The present disclosure encompasses (a) combinations of disclosed aspects and/or embodiments and/or (b) reasonable modifications not shown or described.

BRIEF DESCRIPTION OF THE DRAWINGS [0024] Several embodiments in which the present disclosure can be practiced are illustrated and described in detail, wherein like reference characters represent like components throughout the several views. The drawings are presented for exemplary purposes and may not be to scale unless otherwise indicated.

[0025] Figure 1A is a perspective illustration of an electrophoresis cartridge.

[0026] Figure IB is a perspective exploded illustration of a single gel separation column of the cartridge.

[0027] Figure 2A is an exploded perspective illustration of the components used in the construction of the electrophoresis cartridge.

[0028] Figure 2B is a close-up view of an electrode, showing indentations that allow contact with separation gel.

[0029] Figure 3A is an illustration of a single gel separation column emphasizing the sample loading chamber.

[0030] Figure 3B is an illustration of a portion of a single gel separation lane showing a side view of a sample loading chamber.

[0031] Figure 3C is an illustration of a portion of a single gel separation lane showing atop view of a sample loading chamber.

[0032] Figure 3D is an illustration of a portion of a single gel separation lane showing a side view of an alternative sample loading chamber.

[0033] Figure 3E is an illustration of a portion of a single gel separation lane showing a top view of an alternative sample loading chamber.

[0034] Figure 3F is an illustration of a portion of a single gel separation lane showing a side view of a hydrophobically modified sample loading chamber.

[0035] Figure 3G is an illustration of a portion of single gel separation lane showing a top view of a hydrophobically modified sample loading chamber.

[0036] Figure 4 is a black and white photo of a gel image of a DNA separation generated using the electrophoresis cartridge of Figure 1A.

[0037] Figure 5A is a cut-away view of a gel separation column showing a partial gel-fill operation on the anode side of the cartridge.

[0038] Figure 5B is a cut-away view of a gel separation column showing a fuller partial gel-fill operation on the anode side of the cartridge.

[0039] Figure 5C is a cut-away view of a gel separation column showing a complete gel-fill operation on the anode side of the cartridge.

[0040] Figure 5D is a cut-away view of a gel separation column showing a partial gel-fill operation on the cathode side of the cartridge. [0041] Figure 5E is a cut-away view of a gel separation column showing a complete gel-fill operation on the cathode side of the cartridge.

[0042] Figure 6A is a perspective view of the electrophoresis console.

[0043] Figure 6B is an alternate exploded perspective view of the electrophoresis console.

[0044] Figure 7A is a perspective illustration of the electrophoresis console with a camera hood. [0045] Figure 7B is a perspective illustration of the electrophoresis console with a camera hood showing the camera, electronics, and camera lens.

[0046] An artisan of ordinary skill in the art need not view, within isolated figure(s), the near infinite distinct combinations of features described in the following detailed description to facilitate an understanding of the present disclosure.

DETAILED DESCRIPTION

[0047] The present disclosure is not to be limited to that described herein. Mechanical, electrical, chemical, procedural, and/or other changes can be made without departing from the spirit and scope of the present disclosure. No features shown or described are essential to permit basic operation of the present disclosure unless otherwise indicated.

[0048] Referring now to the figures, a gel electrophoresis cartridge and console with an enhanced workflow for the separation, analysis, and purification of biological materials is shown.

[0049] Types of biological materials and biomolecules used can include double-stranded (ds) DNA, single-stranded (ss) DNA, dsRNA, ssRNA, MRNA, genomic DNA, proteins, and carbohydrates.

[0050] The separation gel may be of any type used in conventional slab gel electrophoresis. Preferred gels include agarose and polyacrylamide.

[0051] Referring to Figure 1A, the gel electrophoresis cartridge 101 has a label, 103 for identifying information such as part number, lot number, run number, sample, etc. A conductive strip 107 is the anode. Conductive strip 108 is the cathode. The cartridge contains at least one separation column 109 (Figure IB) comprising anode chamber 106, cathode chamber 105, separation lane 102, and sample input chamber 104. The anode chamber, 106, cathode camber 105, and separation lane 102 can be filled with a separation electrophoresis gel. There are no separate buffer chambers or liquid overlay in contact with the anode and cathode. The gel serves a dual purpose as a conducting interface with the electrodes and as a separation medium. Sample input chamber 104 is not filled with separation gel, but is instead left empty for subsequent input of sample.

[0052] Sample input chamber 104 is located within separation lane 102, and can be located closer to the cathode chamber 105 than the anode chamber 106. For example, the sample input chamber 104 is located 5 percent of the length of the separation lane from the cathode chamber 105 side. In another example, the sample input chamber 104 is located between 1 percent and 33 percent of the length of separation from the cathode chamber 105 side. Sample input chamber 104 is distanced from the cathode to reduce heat transfer from the electrophoresis electricity into the sample.

[0053] Bufferless slab gel electrophoresis cartridges are known. The present disclosure improves over known bufferless systems in that no liquid or buffer overlay is required. Electrode chambers

105 and 106 have an individual volume equal to or greater than the volume of the separation lane 102. This electrode chamber to channel ratio provides enough buffering to the electrophoresis separation for ions and pH while also keeping the gel cool and limiting it from drying out as the electrophoresis current is applied.

[0054] Figure IB shows a perspective exploded view of an individual separation column 109 comprising anode chamber 106, cathode chamber 105, separation lane 102, and sample input chamber 104. For operation in gel electrophoresis, anode chamber 106, cathode chamber 105 and separation lane 102 are filled with an electrophoresis gel. Sample input chamber 104 is not filled with the separation gel and is left empty for subsequent input of sample solution.

[0055] The preferred anode chamber 106 geometry is approximately 5 millimeters (mm) wide x 8 mm length x 5 mm deep. The preferred cathode chamber 105 is approximately 5 mm wide x 10 mm length x 5 mm deep. The preferred separation lane 102 is approximately 40 mm long x 1.5 mm wide and 1.5 mm deep. The sample input chamber 104 has dimensions of approximately 2.3 mm wide x 1 mm long by 1.8 mm deep. The preferred anode chamber 106 volume is approximately 180 microliters (pL). The preferred cathode chamber 105 is approximately 250 microliters. The preferred separation lane 102 is approximately 100 microliters. The anode and electrode chambers are oversized in the event the operator wants to extend the duration of the separation beyond the recommended run time of 3 to 5 minutes. The preferred sample input chamber 104 a volume is approximately 6 microliters.

[0056] The geometry of the anode and cathode chambers may be any dimensions as long as the ratio of the chamber volumes to channel are sufficient as previously discussed.

[0057] The volume of the sample input chamber 104 may be sized according to the volume of sample analyte and experiment or application type. For example, the sample input chamber 104 could be as large as 100 pL or more to recover relatively large amounts of concentrated and separated sample material. This capability is not possible with microfluidic chips as found in prior art.

[0058] The sample solution (matrix) in which the biological sample is dissolved, suspended, or dispersed may be of any type used in conventional slab gel electrophoresis. [0059] Figure 2A shows the components of a thermoformed gel electrophoresis cartridge 201. Label 103 is added to the cartridge 201 for general information. Conductive strip 108 is the cathode. Conductive strip 107 is the anode. Indentation 206 of the conductive strips 107 and 108 allows the conductive material to contact the conductive electrophoresis gel matrix. Figure 2B shows electrodes 107 or 108 with a section folded down to allow contact with the conducting separation gel matrix. Clear plastic substrate 205 forms the cartridge body, containing the separation lanes 102, cathode chambers 105, anode chambers 106, and sample input chambers 104. Substrate 205 is a translucent or clear moldable plastic. Clear plastic film 203 covers the separation lanes, but partially leaves open the anode chambers 106 and cathode chambers 105 for input and filling of gel matrix. Clear plastic film cover 203 also has a slit opening 202 which allows for sample placement into sample input chambers 104. An alternate clear plastic film cover 204 covers the separation lanes, contains slits 209 as openings to the sample input chambers 104, contains holes 208 for input of gel electrophoresis matrix by pipette tip into the anode chambers 106 and cathode chambers 105, and contains slits 207 and 210 to vent air when filling the anode and cathode chambers with gel.

[0060] Clear plastic film 203 should cover a majority of cathode chamber 105 and anode chamber 106 while still providing access to add gel.

[0061] Although the illustrated shape of the cross-section of the separation chamber is square or rectangular the channel may not necessarily have 3 distinct walls. The channel may be any shape, including U-shaped, round, v-shaped, rectangular shaped, fileted, chamfered, patterned, or irregularly shaped as long as it has 3 dimensions of geometry to sufficiently hold the separation material. All components of the channel and reservoir may have tapered or drafted walls with rounded comers or filets to ease manufacture and mold release.

[0062] Materials used for conductive strips 107 or 108 include but is not limited to copper, platinum, gold, silver, aluminum, steel, tin, graphite, carbon, silver plated conductors, gold plated conductors, nickel plated conductors, tinned conductors, conductive polymers such as polyaniline conductive composites, conductive inks, or conductive adhesives. Conductive materials may be applied using any process including but not limited to vapor deposition, gluing, resist/etching, inkjetting, screen printing, or pad printing. A preferred material is copper or aluminum tape.

[0063] Substrate 205 and film 203 or 204 materials include any thermoset or thermoplastic or any combination of plastic materials that is transparent for the desired analysis. Preferable materials are the thermoplastic resins. An even more preferable material is polypropylene or polystyrene. Layers may be attached to each other using any adhesive known to the art, such as acrylic adhesive or silicone adhesive. For example, the adhesive on film 203 may face the inner cavity of the separation lane 102 and hydrophillically enable surface weting and filling of the gel into the separation lane 102. The adhesive can be substantially transparent to the wavelengths of interest. [0064] For applications in which the biomolecules are detected through ultraviolet absorbance analysis, and where no dye may be required, substrate 205 and film 203 may be made from a UV- transparent plastic such as the Topas™ COC™ polyethylene resins.

[0065] Figure 3B shows the top view of a separation column 109 (Figure IB), with cathode chamber 105, anode chamber 106, separation lane 102 and sample input chamber 104. Figures 3A-G show some possible configurations for the walls of the separation chamber. In particular, the introduction of geometric features into the substrate 205 (Figure 2A) walls in and around the sample input chamber 102 and features in film 203 or 204 prevents the electrophoresis gel from migrating past the boundaries of the sample input chamber, allowing for the creation of an empty chamber for subsequent sample input. An alternate form uses a hydrophobic chemical coating or surface treatment for hydrophobic modification of the walls of the sample input chamber section, which prevents the electrophoresis gel from migrating past the boundaries of the sample input chamber 104, allowing the creation of an empty chamber for subsequent sample input.

[0066] Figure 3B shows a cutaway side view of one possible configuration of the sample input chamber 104 within the separation lane showing an abrupt widening and indentation 307 of substrate 205, which forms a sharp ledge 302 at the side of the sample input chamber. Doted lines 301 show the boundary of the sample input chamber 104 within the separation lane, which is formed when gel is placed into the separation lanes.

[0067] Figure 3C shows a top view of the substrate modification shown in FIG. 3B. Doted lines 301 show the interface between the sample input chamber 104 and the gel placed in the separation lanes. By alteration of surface weting characteristics, sharp ledge 302 prevents gel from migrating into the sample input chamber when gel is placed into the anode and cathode chambers of a separation column.

[0068] Figure 3D shows an alternate modification of substrate 205, showing a cutaway view with an upward indentation forming sharp ledge 303, which alters surface weting characteristics and prevents gel from migrating into the sample input chamber when gel is placed into the anode and cathode chambers of a separation column. Doted lines 301 show the boundary of the sample input chamber, which is formed when gel is placed into the separation lanes.

[0069] Figure 3E shows a top view of the substrate modification shown in Figure 3D. Dotted lines 301 show the wall interface between the sample input chamber and the gel placed in the separation lanes. By alteration of surface weting characteristics, sharp ledge 303 prevents gel from migrating into the sample input chamber when gel is placed into the anode and cathode chambers of a separation column. [0070] Figure 3D shows a cutaway side view of another alternate modification of substrate 205, showing a chemical or surface-treatment hydrophobic modification of the walls (shown as shaded area) of the sample input chamber 104, which alters surface wetting characteristics and prevents gel from migrating into the sample input chamber when gel is placed into the anode and cathode chambers of a separation column.

[0071] Figure 3G shows a top view of the substrate modification as shown in side view Figure 3F. Dotted lines 301 show the wall interface between the sample input chamber and the gel placed in the separation lanes. Chemical or surface treatment hydrophobic modification of the walls of the sample input chamber 104 (shown as shaded area) alters surface wetting characteristics and prevents gel from migrating into the sample input chamber when gel is placed into the anode and cathode chambers of a separation column.

[0072] The passive filling and fluid handling in microfluidic channels by liquid via liquid/ surface interaction is known. See, e.g., “A Review of Capillary Control Valves in Microfluidics” by Wang et. al. Biosensors 2021, 11, 405. Passive capillary valves can stop an advancing flow of liquid by an abrupt widening of the chamber. Example capillary valves are created on the boundary of sample input chamber 104 with sharp angles 302 (Figure 3C), or by an abrupt narrowing of the chamber with sharp angles 303 (Figure 3D). A passive capillary valve may also be made hydrophobic modification of the surface. An example capillary valve is formed by hydrophobic modification of the substrate surface of the sample input chamber 104, shown as the shaded area in Figure 3F.

[0073] Any combination top or side view surface wetting modification examples may be used to prevent sample gel from migrating into the sample input chamber 104.

[0074] Methods of hydrophobically modifying the surface include, but are not limited to, plasma treatment or coating with paraffin, polytetrafluoroethylene (PTFE), polyamide, polycarbonate, polyacrylonitrile, silicone polymer, or fluorocarbon wax.

[0075] Figure 4 shows an image of the separation of a 100 bp-15,000 bp DNA ladder using the electrophoresis device. This is discussed in the example section.

[0076] Figures 5A-5E shows an individual separation column 109 being filled using a pipette 502. Figure 5A shows pipette 502 with electrophoresis gel matrix 503 placed into anode chamber 106. Electrophoresis gel matrix 503 migrates down and fills the separation lane 102 via surface interaction shown in Figure 5B. Figure 5C shows that when the electrophoresis gel matrix 503 reaches ledge 302 (Figure 5C) formed by a shape of the substrate 502, migration of the electrophoresis gel matrix 503 stops, leaving the sample input chamber empty. The wall of the stopped gel 503 defines a wall of the sample input chamber 104. [0077] Figure 5D shows pipette 502 with electrophoresis gel matrix 503 placed into cathode chamber 105. Electrophoresis gel matrix 503 migrates down and fills the separation lane 102 via surface interaction. Figure 5E shows that when the electrophoresis gel matrix 503 reaches the ledge 302 (Figure 3C) formed by a of the substrate 502, migration of the electrophoresis gel matrix 503 stops, leaving the sample input chamber empty. The wall of the stopped gel 503 defines a wall of the sample input chamber 104.

[0078] Electrophoresis can be performed on a sample with a negative charge. Alternatively, a positive sample charge can be utilized however requires the electrical polarity on chambers 105 and 106 to be reversed.

[0079] A particularly beneficial aspect of the present disclosure is the ability of the lab practitioner to load their own custom gel into gel electrophoresis cartridge 101. Users are not tethered to a single gel defined by the cartridge manufacturer, such as agarose, but instead can use custom variants that they currently use in their own standard slab gel electrophoresis, such as agarose or polyacrylamide with varying concentrations, added denaturing agents, or surfactants.

[0080] Figure 6A shows an electrophoresis console 601 for running the electrophoresis gel cartridge 101. Electrophoresis cartridge 101 is slid into electrophoresis console 601, where electrodes 108 and 107 make contact with the instrument via spring pressure connection 610 (Figure 6B). Magnets 607 allow for attachment of emission filter 604, which has magnets 605. The semi-transparent emission filter 604 removes the excitation wavelength light, but allows other light to pass, enabling a user to view electrophoresis separation real time during the electrophoretic separation. A preferred transparent filter is orange transparent plastic, which filters out 450-500 nanometer excitation light. Emission filter 604 also serves as a cover to protect the user from accidental contact with the high voltages applied to the gel electrophoresis cartridge 101. Holes 606 are optionally placed into the emission filter 604 to allow air flow from the fans 609 up and around the excitation filter 608, electrophoresis cartridge 101, and up through the emission filter 604. Air from the fans also flows through the electrophoresis console holes 617, 619 (Figure 6B) located on the rear and back of the unit. LED Lights 602, which may have a variety of different colors for different operational states indicate the status and progress of the electrophoresis run. For example, LED light 602 may turn red for a timed “electrophoresis on" state, whereas no light may indicate an “electrophoresis off’ state. Buttons 603 select the set of conditions used for the electrophoretic separation. For example, one button may have a separation of 3 minutes to 5 minutes with an applied voltage of 165 Volts (V). The system is designed so that pre-programmed separation conditions are entered into the control board 613 (Figure 6B).

[0081] Figure 6B shows a perspective exploded view of the instrument with different components, including a bottom chassis frame 618 that contains an excitation light LED array 616 (e.g. , 460-470 nanometers emission wavelength). Fans 609 provide air flow to cool heat generated by the control board 613, LED light array 616, and gel electrophoresis cartridge 101 containing gel. The control board 613 carries a high voltage electrophoresis power supply, LED driver, microprocessor, and voltage regulation circuitry. Excitation filter 608 allows the excitation wavelengths of interest to pass, blends, and homogenizes the light from the LED array 616 so that electrophoresis cartridge 101 is uniformly illuminated during the electrophoresis. Control board 613 with a high voltage power supply controls the duration of the electrophoresis, as well as the applied voltage. Top cover 612 covers the control board 613 and chassis frame 618. Enclosure 611 includes a support for the electrophoresis cartridge 101, as well as mounting magnets 607 for the attachment of an emission filter top filter plate 604, or camera attachment hood 702 (Figures 7A-7B).

[0082] The electrophoresis console 601 (Figure 6A) applies a voltage to electrophoresis cartridge 101 (Figure 1A) via high voltage power supply on the control board 613 (Figure 6B) and electrodes (107 & 108 Figure 1A). The applied voltage ranges from IV to 250V. The voltage may be applied with a preferred time range of 3-7 minutes.

[0083] Figure 7A shows a camera attachment hood 702 that attaches to the electrophoresis console 601. Electrophoresis cartridge 101 is shown installed in the chassis 601 for this exemplary illustration. Cord 703 supplies power and data to the attached digital camera 705 Figure 7B).

[0084] Figure 7B shows a Camera hood 702, with digital camera, electronics 705 and camera lens 704. Magnets 705 allow for magnetic mounting with magnetic mounts 607 on electrophoresis console 601.

A process for performing electrophoresis

[0085] Using a cartridge 101 (Figure 1A), prepare a 0.8% agarose gel by adding 5 mL of DI water, 100 pL of 50x TAE buffer, and 30mg of agarose powder, mixing and heating to a liquid state (approximate temperature 100 C). The cartridge 101 is loaded into the electrophoresis console 601 (Figure 6). Pipette gel 503 (Figure 5A) into the anode chamber 106. Gel fills the reservoir 106 (Figure 5A). Once the reservoir is filled the gel wicks down the separation channel via surface interaction (Figure 5B) and stops at the edge sample input chamber 104 (Figure 5C). This gel filling process is repeated for the cathode chamber 105. Pipette gel 503 (Figure 5D) into the cathode chamber 105. Gel fills the reservoir 105 (Figure 5D). Once the reservoir is filled the gel wicks down the separation channel (Figure 5E) and stops at the edge sample input chamber 104 (Figure 5E). At this point, an empty cavity with a precise volume has been formed. This is the sample input chamber 104. Once the gel 503 is allowed to cool and solidify for approximately 3 minutes, a biological sample in the appropriate matrix is loaded into the sample input chamber 104. The run conditions are selected using console buttons 603, and a voltage is applied to the cartridge. The pre-programmed conditions of the console sets the run time (i.e., 3 minutes). At any time, the operator may turn on the excitation backlight 616 (Figure 6B) and visualize the sample migration through the instrument’s emission filter 604 (Figure 6A). After the run is over, the operator may remove the sample and use common tools (razor blade, scissors) to excise the sample peaks/bands/fragment(s) of interest from the separation lane. For another run using the same cartridge, the operator can cut the separation column and use another fresh separation column or allow a used lane to dry out, severing electrical connectivity on the used separation column 109. Alternatively, the operator can use a fresh cartridge 101 (Figure 1A).

[0086] Biological samples may be tracked using any visual dye or fluorescent dye currently used in slab gel electrophoresis or capillary electrophoresis. The dye may be a direct staining dye spiked into the sample, or added to the gel. If added to the gel, it has a short shelf life of approximately 2 weeks. The dye may conjugate/associate/intercalate with the DNA/RNA/protein. Examples of gel dye include but are not limited to Ethidium Bromide, SYBR Gold, SYBR Green, SYBR Safe, Eva Green, and Gelstar. Multiple dyes with different wavelengths may be multiplexed within the same sample and run. Different optical filters may be required for different dyes. Other dyes may include but are not limited to FAM, NED, ROX, VIC, HEX, TAMRA, JOE. A preferred dye is the type that is added directly to the sample.

EXAMPLE

[0087] A solution of 1% agarose was prepared using 5mL of DI water, lOOuL of 50x TAE buffer, and 45mg of Fisher Scientific UltraPure™ Agarose. The solution was stirred and microwaved twice for 20 seconds until the solution was water clear. This stock solution of gel is good for several weeks, and can be melted/cooled over 10 times without adverse effect on performance. Cartridge 101 consists of 4 separation columns 109 which are capable of holding 250 pL of gel per column on the anode chamber and cathode chamber sides, therefore making an entire cartridge 101 consume only 2 mL of gel. The sample was prepared by mixing 2 pL of a proprietary direct DNA stain dye with 1.5 pL Invitrogen™ 1Kb Plus DNA Ladder, and 48 pL of DI water.

[0088] The gel cartridge 101 (Figure 1A) was loaded into the electrophoresis console 601 (Figure 6A). The electrophoresis cartridge was then loaded with gel by pipetting approximately 250 pL of the heated (approximately 70-100 degrees Celsius) prepared molten agarose gel into the anode chamber and 250 pL gel into the cathode chamber. The gel migrated into and filled the separation lane, up to the capillary valve points. At this point, a sample chamber 104 (Figure 5E) was fully formed, with the walls of the gel forming the walls of the sample chamber. The gel was allowed to cool and solidify for 3 minutes. 6 pL of the prepared ladder sample solution was loaded into the sample input chamber. The console 601 (Figure 6A) button 603 was pressed enabling a voltage of 165 volts for 5 minutes. The gel was imaged using the LED illuminator of console 601 (Figure 6A). The results, shown in Figure 4, demonstrate excellent separation of double-stranded DNA fragments. An alternate method for tracking the progress of the DNA sample is to add blue loading dye into the sample input chamber prior to run initiation.

[0089] From the foregoing, it can be seen that the present disclosure accomplishes at least all of the stated objectives.

[0090] Various modifications and variations to the present disclosure can be made without departing from the spirit of the discovery or scope of the appended claims.