BACKGROUND

[0001] Analytic chemistry is a field of chemistry that uses instruments to separate, identify, quantify, and study matter. Biochemistry is a field of chemistry that includes the study and analysis of the chemistry of living organisms such as cells. Cell lysis is a process of rupturing the cell membrane to extract intracellular components for purposes such as purifying the components, retrieving deoxyribonucleic acid (DNA), ribonucleic acid (RNA), proteins, polypeptides, metabolites, or other small molecules contained therein, and analyzing the components for genetic and/or disease characteristics. Cell lysis bursts a cell membrane and frees the inner components. The fluid resulting from the bursting of the cell is referred to as lysate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The accompanying drawings illustrate various examples of the principles described herein and are part of the specification. The illustrated examples are given merely for illustration, and do not limit the scope of the claims.

[0003] Fig. 1 is a block diagram of a sample preparation device with an input port cap, according to an example of the principles described herein.

[0004] Fig. 2 is a block diagram of a sample preparation device with an input port cap, according to an example of the principles described herein. [0005] Fig. 3 is an isometric cross-sectional view of a cartridge with multiple sample preparation devices, according to an example of the principles described herein.

[0006] Fig. 4 is an isometric view of a sample preparation device with an input port cap, according to an example of the principles described herein. [0007] Fig. 5 is an exploded view of a sample preparation device with an input port cap, according to an example of the principles described herein. [0008] Fig. 6 is a cross-sectional isometric view of a sample preparation device with an input port can, according to an example of the principles described herein.

[0009] Figs. 7 A and 7B are views of an open input port cap, according to an example of the principles described herein.

[0010] Figs. 8A and 8B are views of an open input port cap, according to another example of the principles described herein.

[0011] Figs. 9A - 9C are views of a vent plug, according to an example of the principles described herein.

[0012] Fig. 10 is a flow chart of a method of sealing a sample preparation device, according to an example of the principles described herein.

[0013] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION

[0014] Cellular analytics is a field of chemistry that uses instruments to separate, identify, quantify, and study cells and their internal components matter. A wealth of information can be collected from a cellular sample. For example, a study of a patient’s cell may lead to diagnosis of diseases of a patient. As a particular example, cellular analysis may be used to detect viral nucleic acid such as those that cause the flu. Moreover, study of cells may lead to the development of medications to treat certain diseases and disorders. [0015] The intracellular components of the cell also provide valuable information about a cell. Cell lysis is a process of extracting intracellular components from a cell and can also provide valuable information about a cell. During lysis, the intracellular components are extracted for purposes such as purifying the components, retrieving DNA and RNA proteins, polypeptides, metabolites, and small molecules or other components therein, and analyzing the components for genetic and/or disease characteristics. Cell lysis ruptures a cell membrane and frees the inner components. The fluid containing the inner components is referred to as lysate. The contents of the cell can then be analyzed by a downstream system. Prior to analysis, the sample to be analyzed is prepared. During preparation, the sample may be lysed and components of the lysate may be bound to magnetic microparticles. Other operations may also be carried out to prepare the same for cellular analysis.

[0016] That is, in biological assays, a biological component can be intermixed with other components in a biological sample that can interfere with subsequent analysis. As used herein, the term “biological component” may refer to materials of various types, including proteins, cells, cell nuclei, nucleic acids, bacteria, viruses, or the like, that can be present in a biological sample. A “biological sample” may refer to a fluid or a dried or lyophilized material obtained for analysis from a living or deceased organism. Isolating the biological component from other components of the biological sample may permit subsequent analysis without interference and may increase an accuracy of the subsequent analysis. In addition, isolating a biological component from other components in a biological sample may permit analysis of the biological component that would not be possible if the biological component remained in the biological sample. In some examples, the biological component of interest that will be bounded to the magnetic microparticles are nucleic acids (such as DNA and RNA).

[0017] While cellular analytics is useful in cellular analysis, refinements to the operation may yield more detailed analysis results. For example, there are many sources of potential contamination of a sample. Cross-contamination may compromise the integrity of a sample and the results of an analysis of the sample. Accordingly, preventing cross-contamination of samples for a given process may ensure the accuracy of sample analysis.

[0018] One source of contamination may arise as a user opens and closes an input cap. That is, via an input port, a user may introduce a sample into the sample preparation device. A cap of the input port may be opened via a single surface. Accordingly, a user may contact a single surface more than one time (e.g., during opening and closing), which may result in potential crosscontamination of samples. That is, if the user touches a single surface multiple times, the user may unknowingly contaminate the surface. Should the contact surface to open and close the input port be in close proximity of the contact surface for the sample pipette into input port, a user may have a higher likelihood of contaminating their gloves with a sample, thereby spreading active sample to the subsequent input port for the next sample. Should this event occur, sample integrity and test results may be compromised. For example, if a user touches an under-side of the cap, the side that when closed could contact the sample, contamination of the sample may occur. This may be particularly possible in an example with a multi-device cartridge. For example, for a first sample preparation device, a user may contaminate their glove. When the user opens the second preparation device, that glove contacts the inside surface of the cap with the sample from the first preparation device.

[0019] As a particular example, the input port region may be small and a user may be wearing one or two pair of gloves for safety reasons. As a result of these conditions, dexterity may be reduced, which may increase a likelihood of inadvertent contamination. The present device prevents the cross-contamination of samples during sample input, even when dexterity may be reduced. Specifically, different surfaces are provided for opening and closing the cap such that the same surface is not touched more than once. Ensuring a user does not contact the same surface more than once reduces a likelihood of cross-contamination across these surfaces. [0020] Moreover, upon unlatching, the input port cap of the present device biases to a particular open angle. This provides the user a visual indicator that the input port cap is ready to receive a sample. The biasing may be effectuated via a cantilever spring and a retention mechanism that interferes when the input cap is closed and latched. The spring provides the potential energy to lift the lid once it is unlatched by the user.

[0021] In some examples, the input port cap may be a single molded component, thus providing a low part count. An integrated component also provides a streamlined and efficient assembly process which may reduce the waste stream for the environment.

[0022] The molded input port cap may be closed and latched in a manufacturing process prior to being press fit into the input port throat. Before the closed cap is pressed on, a seal component is placed into the input port throat. The input port cap is then pressed on, aligning a keyed surface on the input port with the key on the input port cap. During use, a user would press a trigger to open the input port cap, without touching the input port cap lid. As a result of the spring loading, the input cap port may open, providing a visual cue that the input port is ready to receive a sample. After a user inserts the sample into the mixing chamber through the input port, the input port is sealed responsive to a user pressing the lid without touching the trigger. Accordingly, different surfaces are provided for opening and closing the input port cap, thus sealing a sample preparation device while reducing the likelihood of crosscontamination.

[0023] Specifically, the present specification describes a sample preparation device. The sample preparation device includes a mixing chamber to receive a sample, an input port to introduce the sample into the mixing chamber, and a seal component disposed within the input port. The sample preparation device also includes an input port cap. The input port cap includes 1 ) a lid to selectively cover the input port, 2) a retention mechanism to keep the lid disposed over the input port, and 3) a trigger as a first contact surface to open the lid. The lid is closed via user depression of the lid as a second contact surface. [0024] In an example, the retention mechanism includes a protrusion on the lid to interact with a protrusion coupled to the trigger. In an example, the trigger aligns with the protrusions coupled to the trigger. In another example, the trigger is offset from the protrusions coupled to the trigger.

[0025] The input port cap may be an integrated molded device formed of a single material. In an example, the sample preparation device includes a spring to bias the lid towards an open position when the trigger releases the retention mechanism. The spring may be integrated with the input port cap as a single molded device.

[0026] In an example, the sample preparation device includes a vent plug disposed within the input port cap to seal against the seal component. In an example, the lid includes a vent to maintain a predetermined pressure in the mixing chamber. The vent may be covered by a membrane to prevent liquid escape. The vent plug may include a labyrinth race to reduce humidity transfer. [0027] In an example, the sample preparation device includes a mixer disposed within the mixing chamber to agitate the sample and an actuator to transmit a torque from a motor to the mixer. The sample preparation device also includes a seal to separate the mixing chamber from a downstream component and a plunger disposed within the mixing chamber to direct contents of the mixing chamber to the downstream component.

[0028] The present specification also describes a method. According to the method, an input port cap is to cover an input port of a mixing chamber of a sample preparation device. The input port cap is opened, via activation of a trigger at a first contact surface of the input port cap, to expose the mixing chamber to a sample input device. According to the method, the input port cap is closed, via activation at a second contact surface of the input port cap to selectively seal the mixing chamber. In an example, a spring rotates the input port cap at least 90 degrees.

[0029] In another example, the sample preparation device includes a mixing chamber to receive a sample and an input port to introduce the sample into the mixing chamber. The sample preparation device includes an input port seal disposed within the input port. The sample preparation device also includes an input port cap. The input port cap includes 1) a concave lid to selectively cover the input port, 2) a retention mechanism to keep the lid disposed over the input port, 3) a trigger as a first contact surface to open the lid, and 4) an integrated spring to bias the lid towards an open position. The lid is closed via user depression of the lid at a second contact surface. The sample preparation device also includes a fluid isolation chamber to receive the contents of the mixing chamber and to house a reaction and an output to dispense contents of the fluid isolation chamber.

[0030] In an example, the sample preparation device is disposed in a cartridge along with other sample preparation devices. The cartridge is insertable into a host station. In an example, the concave lid and trigger are color-coded to identify an open and close action to be carried out at that location.

[0031] In summary, such a sample preparation device 1) provides two separate surfaces for opening and closing of the cap lid to reduce the likelihood of cross-contamination of samples, 2) upon unlatching, opens to a given angle, providing visual feedback to the user that the sample input port is ready to receive sample, 3) reduces the number of components, thereby reducing the consumable waste stream, 4) provides the same consistent press action, against the consumable, for both opening and closing of the sample input cap; and 5) simplifies assembly operations. However, the devices disclosed herein may address other matters and deficiencies in a number of technical areas. [0032] Turning now to the figures, Fig. 1 is a block diagram of a sample preparation device (100) with an input port cap (108), according to an example of the principles described herein. As described above, a sample may be prepared before it is analyzed or processed. Such preparation may include lysing a sample and binding a specific element in the lysate, such as for example nucleic acid, to magnetic microparticles. In some examples, the magnetic microparticles are paramagnetic microparticles; in some other examples, the magnetic microparticles are paramagnetic beads. The sample preparation device (100) of the present specification carries out at least a portion of this sample preparation. Specifically, the sample preparation device (100) includes a mixing chamber (102), which is a volume, to receive the sample. In some examples, the sample may be a biological sample, that is the sample may include biological components to be studied and analyzed. Within the mixing chamber (102), operations such as lysing and binding a specific element present in the lysate, such as for example nucleic acid, to magnetic microparticles are performed. In general, lysis refers to the rupturing a cell membrane. Such rupture may be mechanical, for example via agitation, or chemical, for example via introduction of a chemical reagent. Lysis ruptures a cellular particle membrane and frees the biological components. The fluid containing the biological components is referred to as lysate. The contents of the cellular particle can then be analyzed by a downstream system.

[0033] The cells within the biological sample may be lysed in a number of ways. For example, the cells may be lysed by heating the walls of the mixing chamber (102) which causes the cells to rupture. In some examples, the mixing chamber (102) may also include a chemical compound that causes the cell membranes to rupture. That is, in addition to being a volume wherein the sample is mixed with a reagent, the mixing chamber (102) may store the reagent to be used. Accordingly, during manufacture, a reagent may be deposited in the mixing chamber (102) rather than being input as part of the sample preparation operation.

[0034] Once lysed, a component of the lysate, for example the nucleic acid, may be bound to magnetic microparticles that are disposed within the mixing chamber (102).

[0035] Specifically, the magnetic microparticles may be disposed in a pellet with a dissolving membrane. Specifically, when a sample is introduced into the mixing chamber (102) it may dissolve the pellet, spilling the magnetic microparticles contained therein.

[0036] The magnetic microparticles within the pellet may be paramagnetic microparticles, superparamagnetic microparticles, diamagnetic microparticles, or a combination thereof, for example. As used in the present specification, the term magnetic microparticles may include microparticles that may not be magnetic in nature unless and until a magnetic field is introduced at a strength and proximity to cause them to become magnetic. The magnetic strength of the magnetic microparticles may be dependent on the magnetic field applied and may become stronger as the magnetic field is increased, or as the magnetic microparticles move closer to the magnetic source that is applying the magnetic field.

[0037] Specifically, paramagnetic microparticles may be those that have the ability to increase in magnetism when a magnetic field is present; however, paramagnetic microparticles are not magnetic when a magnetic field is not present. In some examples, the paramagnetic microparticles may exhibit no residual magnetism once the magnetic field is removed. A strength of magnetism of the paramagnetic microparticles may depend on the strength of the magnetic field, the distance between a source of the magnetic field and the paramagnetic microparticles, and a size of the paramagnetic microparticles. [0038] Superparamagnetic microparticles may be similar to paramagnetic microparticles, however, they may exhibit magnetic susceptibility to a greater extent than paramagnetic microparticles in that the time it takes for them to become magnetized appears to be shorter. Diamagnetic microparticles may display magnetism due to a change in the orbital motion of electrons in the presence of a magnetic field.

[0039] As described above, the magnetic microparticles may be surface- activated to selectively bind with a biological component or may be bound to a biological component from a biological sample. In a specific example, an exterior of the magnetic microparticles may be surface-activated with interactive surface groups that can interact with a biological component of a biological sample or may include a covalently attached ligand.

[0040] In some examples, the ligand may include proteins, antibodies, antigens, nucleic acid primers, nucleic acid probes, amino groups, carboxyl groups, epoxy groups, tosyl groups, sulphydryl groups, or the like. In one example, the ligand may be a nucleic acid probe. The ligand may be selected to correspond with and to bind with the biological component. The ligand may vary based on the type of biological component targeted for isolation from the biological sample. For example, the ligand may include a nucleic acid probe when isolating a biological component that includes a nucleic acid sequence. In another example, the ligand may include an antibody when isolating a biological component that includes antigen.

[0041] In some examples, the magnetic microparticles can have an average particle size ranging from 10 nanometers (nm) to 50,000 nm. In yet other examples, the magnetic microparticles may have an average particle size ranging from 500 nm to 25,000 nm, from 10 nm to 1 ,000 nm, from 25,000 nm to 50,000 nm, or from 10 nm to 5,000 nm. As used in the present specification, the term “average particle size" describes a diameter or average diameter, which may vary, depending upon the morphology of the individual particle. A shape of the magnetic microparticles may be spherical, irregular spherical, rounded, semi-rounded, discoidal, angular, sub-angular, cubic, cylindrical, or any combination thereof. The shape of the magnetic microparticles may be spherical and uniform, which may be defined herein as spherical or near- spherical, e.g., having a sphericity of >0.84. Thus, any individual particles having a sphericity of <0.84 are considered non-spherical (irregularly shaped). [0042] A mixer disposed within the mixing chamber (102) may stir the contents of the mixing chamber to aid and expedite the lysing operation. Such mixing also places the lysate and the magnetic microparticles in proximity to one another such that they may bind together. For example, the magnetic microparticles may be heavier than the solution in the mixing chamber (102) and may otherwise settle to the bottom of the mixing chamber (102). The mixer introduces turbulence that distributes the magnetic microparticles more uniformly throughout the matrix of the solution such that there are more opportunities for the magnetic microparticles to bind with a specific component of the lysate.

[0043] The sample preparation device (100) includes an inlet port (104) to introduce the sample into the mixing chamber (102). The inlet port (104) may include an opening sized to receive a tip of a pipette. For example, a pipette may contain a sample to be inserted into the mixing chamber (102) for preparation. A user may insert the tip of the pipette into the input port (104) and depress a bulb on the pipette to drive the contents into the mixing chamber (102) through the input port (104). Disposed within the input port (104) is a seal component (106). The seal component (106) may reduce the presence of trapped sample during ejection. For example, the seal component (106) may include sloped sidewalls such that fluid from the pipette is directed towards an opening in the input port (104) and does not get stuck in corners of the input port (104).

[0044] The sample preparation device (100) also includes an input port cap (108) that is to cover the input port (104) when not in use, and that can be selectively opened to allow a pipette to introduce a sample into the mixing chamber (102). That is, when not in use, it may be desirable for an input port (104) to be sealed to prevent leakage of the sample and/or to prevent contamination of the mixing chamber (102) volume by environmental contaminants. Moreover, in some cases it may be desirable to maintain a certain pressure in the mixing chamber (102). The input port cap (108) provides the selective opening of the input port (104) as a sample is introduced. The input port cap (108) also seals the mixing chamber (102) when no sample is being introduced and when an operation such as mixing, heating, and/or binding is occurring within the mixing chamber (102).

[0045] The input port cap (108) includes various components to facilitate a contamination-free sample insertion. Specifically, the input port cap (108) includes a lid (110) that covers the input port (104). The lid (110) may provide a liquid-tight seal wherein fluid and particulate matter cannot ingress or egress through the lid (110) when in a closed position. As described below, in some examples, the lid (110) includes a vent through which air may pass.

[0046] The input port cap (108) also includes a retention mechanism to keep the lid (110) disposed over the input port (104) when not in use. That is, in order to function as a seal, the lid (110) should be able to be retained over the input port (104). The retention mechanism (112) provides this seal and maintains the lid (110) in a closed position when the input port (104) is not in use.

[0047] The input port cap (108) also includes a trigger (114) to act as a first contact surface which opens the lid (110). That is, as described above, in order to prevent cross-contamination, the input port cap (108) provides two separate surfaces, one that is contacted when opening the input port cap (108) and another that is contacted when closing the input port cap (108). Keeping these two surfaces separate from one another ensures that a user touches one surface to open the input port cap (108) and a different surface to close the input port cap (108), thus preventing potential cross-contamination. The lid (110) is closed via user depression of the lid (110) itself. That is, the lid (110) acts as a second surface to close the input port cap (108). Accordingly, during use, to open the input port cap (108), a user activates the trigger (114) without contacting the lid (110). To close the input port cap (108), the user depresses the lid (110) without contacting the trigger (114).

[0048] Fig. 2 is a block diagram of a sample preparation device (100) with an input port cap (108), according to an example of the principles described herein. As in the previous example, the sample preparation device (100) may include a mixing chamber (102), input port (104), seal component (106), and input port cap (108) as described above. In this example, the lid (110) may be concave to match the ergonomics of a user finger.

[0049] In this example, the input port cap (108) may further include an integrated spring (216) to bias the lid (110) towards an open position. That is, to prevent further user contact, the lid (110) may open to a sufficient angle that a pipette may be inserted without the user having to manually open the lid (110) further. That is, were a user to touch the lid (110) to open the lid (110) enough such that the pipette could be introduced, cross-contamination may still result as the user 1 ) contacts the lid (110) to expose the input port (104) and 2) contacts the lid (110) to close the input port cap (108). Accordingly, an integrated spring (216), which may be a deflecting member, may bias the lid (110) to an open position. For example, the spring (216) may rotate the lid (110) more than 90 degrees from an initial position, such that the pipette may be introduced without additional manipulation of the lid (110) by the user.

[0050] The sample preparation device (100) may also include a fluid isolation chamber (218) to receive the contents of the mixing chamber (102) The fluid isolation chamber (218) provides a fluid path for collecting the magnetic microparticles (using external magnets) out of the lysate, pulling the magnetic microparticles towards the output (220), and eventually dispensing them into the waiting receptacle for analysis. The magnetic microparticles may also be cleaned in the fluid isolation chamber (218). In some examples, within the fluid isolation chamber (218), the lysate may be mixed with a reagent.

[0051] The sample preparation device (100) may also include an output (220) to dispense the contents of the fluid isolation chamber (218). That is, as described above, the sample preparation device (100) may prepare the sample for analysis. The outlet (220) of the sample preparation device (100) may eject the prepared sample onto a surface such that the analysis may be performed. In an example, the surface may be a well plate with individual wells.

[0052] Fig. 3 is an isometric cross-sectional view of a cartridge (322) with multiple sample preparation devices (Fig. 1 , 100), according to an example of the principles described herein. As described above, in some examples, the host station may prepare multiple samples in parallel. For example, as described above, each sample preparation device (100) analyzes a single sample. Accordingly, multiple parallel sample preparation devices (Fig. 1 , 100) allow multiple samples to be analyzed at the same time, rather than analyzing a single sample at a time.

[0053] Accordingly, the sample preparation devices (Fig. 1 , 100) may be disposed in a cartridge (322) along with other sample preparation devices (Fig.

1 , 100). The cartridge (322) is insertable into the host station, which host station provides the signals and mechanical forces to 1) activate the mixer (328) to lyse the sample, 2) rupture the seal (330), and 3) eject the prepared sample on to a surface.

[0054] To facilitate the mixing and lysing, various components are disposed in the mixing chamber (102). Specifically, the sample preparation device (Fig.

1 , 100) includes a mixer (328) to agitate the sample. The mixer (328) may include a mixing head, blade, or paddle on the end of the shaft. The mixer (328) is rotated by a motor in the host station in which the sample preparation device (Fig. 1 , 100) is installed. [0055] The sample preparation device (100) also includes an actuator (324) to transmit a torque from the motor of the control device to the mixer (328). That is, the actuator (324) provides an interface through which this motion is imparted to the mixer (328). On one end, the mixing cap (324) may include interface surfaces to interact with a driving shaft of the host station and therefore to be driven by the driving shaft.

[0056] The sample preparation device (Fig. 1 , 100) also includes a seal (330) to separate the mixing chamber (102) from a downstream component. In an example, the downstream component is a fluid isolation chamber (218) where additional operations are performed. For example, in the fluid isolation chamber (218), the lysate and magnetic microparticles may be combined with a reagent. As another example, the sample may be concentrated and purified within the fluid isolation chamber (218). For example, the sample may be purified by a density gradient within the fluid isolation chamber (218) and magnetic motion imparted within the fluid isolation chamber (218). Furthermore, coupled to the fluid isolation chamber (218) may be liquid reagents such as master mix to further process the sample.

[0057] Prior to lysing and binding, it may be desirable to seal the mixing chamber (102) to prevent flow out of the mixing chamber (102). Accordingly, the mixing chamber (102) includes a seal (330). Upon rupture of the seal (330), the contents flow to the fluid isolation chamber (218) for further preparation. [0058] In this example, the sample preparation device (100) also includes a plunger (326) disposed within the mixing chamber (102). The plunger (326) operates to open the seal (330) and direct the contents of the mixing chamber (102) to the downstream component. That is, once mixed, the seal (330) may be opened. The force of gravity may draw the fluid through the fluid isolation chamber (218). This motion may be accelerated by the plunger (326) which is then activated to push the contents out. As described above, the motion of the plunger (326) is controlled by the motor and the actuator (324).

[0059] The output (220) may include an air blister. As the air blister is depressed, pressure forces the fluid out the sample preparation device (Fig. 1 , 100) and onto the surface, such as a well plate. [0060] Specific examples of the operation of the sample preparation device (Fig. 1 , 100) are now provided. As a general example, a swap sample may be eluted into a transport medium. The sample may then be prepared, for example by lysing the cell which contains nucleic acid and binding the nucleic acid to magnetic microparticles . The nucleic acids may then be mixed with a master mix. At this stage the prepared sample may be ejected onto a surface, such as a titration plate where the samples may be further processed, for example by performing PCR analyses in cases where magnetic microparticles are bound to nucleic acids.

[0061] As a more specific example, a swab with a sample may be inserted into a transport vial where it is eluted into a medium. A portion of the sample is introduced, for example via a pipette, into the mixing chamber (102) via the input port (104). Introduction of the sample dissolves a holding pellet and releases the magnetic microparticles disposed therein. The sample may be sequentially and/or simultaneously heated, via heat blocks heating walls of the mixing chamber (102) and rotation of the mixer (328). The sample is lysed by heating the sample to a temperature of 80 degrees Celsius (°C) which in one example ruptures the membrane walls spilling the lysate. At this point, the lysate may be cooled to a temperature of around 56 °C in an example, all while mixing the sample. A chemical reaction binds a component of the lysate, such as a nucleic acid, to the magnetic microparticles . Increased binding is provided via action of the mixer (328) to agitate the biological sample providing greater interaction between the sample lysate and the magnetic microparticles .

[0062] At some point prior to rupturing of the seal (330), a wash buffer may be introduced into the fluid isolation chamber (218). A wash buffer refers to a composition that may wash the magnetic microparticles of impurities that may be in the sample and that may inhibit downstream processes such as PCR. The wash buffer also forms a continual fluid path from the lysate to the output (220). Such a wash buffer may rinse the nucleic acid/magnetic microparticles , removing a reagent and preparing the sample for application of another agent. In an example, the wash buffer may include water, some salts to control pH, other salts to help keep the nucleic acids stay bound to the magnetic microparticles , a surfactant to help keep the magnetic microparticles distributed, and preservatives/biocides. In some examples, the wash buffer may include a densifier such as iodixanol to create the density gradient-based purification method in the fluid isolation chamber (218). In other examples, the wash buffer may include alcohol (ethanol or isopropanol), oils, other surfactants, etc.

[0063] The lysate, which may be a biological sample, may then be introduced into the fluid isolation chamber (218) via action of the mixer (328) to rupture the seal (330) and the plunger (326) to drive the fluid. As described above, this motion is driven by the motor and transmitted to the mixer (328) and the plunger (326) via the actuator (324).

[0064] When in the fluid isolation chamber (218), certain operations may be performed to further process the sample. Once prepared, the sample may be ejected via the output (220) to be subsequently analyzed.

[0065] Fig. 4 is an isometric view of a sample preparation device (100) with an input port cap (108), according to an example of the principles described herein. Specifically, Fig. 4 depicts the mixing chamber (102) and the protruding input port (104). Fig. 4 also clearly depicts the input port cap (108). As described above, the input port cap (108) includes a trigger (114) which acts as a first contact surface. The trigger (114) disengages a retention mechanism (Fig. 1 , 112) such that the lid (110) opens to expose the input port seal (Fig. 1 , 106) to a pipette for sample introduction. As described above, the lid (110) may include an ergonomically concave surface on the front portion to provide a visual cue and ergonomic surface to support closing of the lid (110) following sample injection. In one example, the concave lid (110) and the trigger (114) may be color-coded to identify an open and close action to be carried out at that location. For example, the trigger (114) may be indicated with one color, such as green to indicate the trigger (114) as a contact surface to open the lid (110). Similarly, the concave lid (110) may be indicated with another color, such as red, to indicate the concave surface of the lid (110) as a contact surface to close the lid (110). [0066] In an example, the input port cap (108) is an integrated molded device formed of a single material. For example, the input port cap (108) rather than being made up of multiple components that are assembled together, may be formed via injection molding where a mold is filled with a liquid material that is hardened to form the lid (110), retention mechanism (Fig. 1 , 112), trigger (114), and the integrated spring (Fig. 2, 216). Doing so may reduce the part count and manufacturing operations to form the input port cap (108).

[0067] Fig. 5 is an exploded view of a sample preparation device (100) with an input port cap (108), according to an example of the principles described herein. Specifically, Fig. 5 depicts the actuator (324) which, along with the driving shaft of the host station, allows spinning of the mixer (328) as well as translation of the mixer (328) and/or plunger (326). As described above, the mixer (328) is used to mix magnetic microparticles or a reagent with the sample. The mixing also aides in heating and cooling of the sample during lysing.

[0068] As depicted in Fig. 5, the mixer (328) shaft aligns longitudinally with the mixing chamber (102) and passes through the plunger (326). That is, the mixer (328) shaft passes through a bore in the plunger (326) such that the plunger (326) may translate independently of the mixer (328). Fig. 5 also depicts the seal (330) that is ruptured by the mixer (328) to allow contents to pass to the fluid isolation chamber (Fig. 2, 218). As described above, in some examples, the mixer (328) may be used to open up the seal (330). That is, the seal (330) may be opened with the mixer (114) such that the lysate flows from the mixing chamber (104) into the fluid isolation chamber (Fig. 2, 218).

[0069] In an example, the combined length of the plunger (326) and the actuator (324) is to fit within the mixing chamber (102) but not block the input port (104) opening during lysing. The plunger (316) and actuator (324) may block the passage from the input port (216) to the mixing chamber (102) following plunging.

[0070] In an example, the mixer (328) head is close to the film, for example, between 0.1 and 1.5 millimeters above the seal (330). Doing so increases the efficiency of mixing. That is, the magnetic microparticles may settle. Any magnetic microparticles below the mixer (328) may not be under the influence of the mixer (328) and thus may not mix with the sample. Accordingly, placing the mixer (328) close to the seal (330) reduces the space wherein magnetic microparticles may settle or otherwise be inactive.

[0071] Fig. 5 also depicts an exploded configuration of the input port assembly. Specifically, Fig. 5 depicts the seal component (106) that is pressed into the input port (104). As described above, the seal component (106) may have internal walls that taper towards the mixing chamber (102) to prevent stranding portions of the sample within the input port (104).

[0072] Fig. 5 also depicts the input port cap (108) with its associated components. In some examples, the sample preparation device (100) further includes a vent plug (532) that is disposed within the input port cap (108) to seal against the seal component (106). In some examples, a membrane (534) is also disposed inside the input port cap (108) to prevent liquid escape.

[0073] Fig. 5 also depicts additional components of the plunger (326). Specifically, the plunger (326) may include O-ring seals (537-1 , 537-2) that seal the sample within the mixing chamber (102). That is, the O-ring seals (537-1 , 537-2) create a seal that allows the plunger (326) to move to expel the contents of the mixing chamber (102), all while preventing sample fluid from leaking out the sample preparation device (100). The O-ring seals (537) may be made of a deformable and elastic material. The O-ring seals (537-1 , 537-2) by creating a seal prevent air/fluid escape such that a pressure may be used to expel the contents of the mixing chamber (102) towards the preparation chamber (Fig. 2, 218).

[0074] Fig. 6 is a cross-sectional isometric view of a sample preparation device (100) with an input port cap (Fig. 1 , 108), according to an example of the principles described herein. Fig. 6 clearly depicts the actuator (324) and its interface with the mixer (328). Fig. 6 also depicts the plunger (326) and mixing chamber (102).

[0075] As depicted in Fig. 6, an seal component (106) is placed inside the input port (104) and has tapered walls to direct an input sample into the mixing chamber (102) and to prevent the sample from becoming stranded in the input port (104) region. In some examples, the input port (104) may include a vent to allow air exchange during the sample input such that the sample flows freely into the mixing chamber (102).

[0076] Fig. 6 also depicts the lid (110) which may have a vent (636) to allow air to escape. That is, during lysing and/or binding, pressure may build up in the mixing chamber (102). The vent (636) in the lid (110) may allow air/gas to escape to prevent over pressurization of the mixing chamber (102) during heating, lysing, and/or binding. However, to prevent the escape of the sample through the vent (636), the input port cap (108) includes a membrane (534). That is, the membrane (534) may be formed of a material, such as a fibrous mesh that allows air to escape, but prevents liquid such as the sample from escaping. As a particular example, the membrane (534) may be formed of a material such as polytetrafluoroethylene.

[0077] Fig. 6 also depicts the vent plug (532). The vent plug (532) may include a tortuous path to reduce humidity transfer after unpackaging, for example to ensure that any reagents, such as functionalized pellets, may remain dry. Specifically, a small diameter or small cross-sectional area channel that is long may reduce the rate of transfer of the water molecules from the outside environment to the inside of the mixing chamber (102). That is, the tortuous path slows the transfer of water vapor into the mixing chamber (102) once the cassette packaging has been opened. Reducing the onset of humidity may ensure the integrity of the holding pellet with magnetic microparticles . Without a tortuous path, a freely vented mixing chamber (102) may allow rapid humidization of the pellet, prematurely exposing the magnetic microparticles . [0078] Fig. 6 also clearly depicts the retention mechanism (Fig. 1 , 112) that operates to keep the lid (110) disposed over the seal component (106) when not in use. In this example, the retention mechanism (112) includes a protrusion (638-2) on the lid (11 ) that interacts with a protrusion (638-1 ) coupled to the trigger (114). Accordingly, as a user depresses the trigger (114), the protrusions (638) disengage from one another such that a biasing spring (Fig. 2, 216) may press the lid (110) to an open position, which may include rotation of more than 90 degrees such that the pipette may be inserted and eject its contents into the input port (104) without the user further engaging with the lid (110).

[0079] Figs. 7 A and 7B are views of an open input port cap (Fig. 1 , 108), according to an example of the principles described herein. Specifically, Fig. 7A is an isometric view of the input port cap (Fig. 1 , 108) and Fig. 7B is a cross- sectional view of the input port cap (Fig. 1 , 108). As depicted in Fig. 7A and 7B, the trigger (114) does not align with the protrusions (638) coupled to the trigger (114). Fig. 7A also clearly depicts the spring (216) as being integrated with the input port cap (Fig. 1 , 108) components.

[0080] Figs. 8A and 8B are views of an open input port cap (Fig. 1 , 108), according to another example of the principles described herein. Specifically, Fig. 8A is an isometric view of the input port cap (Fig. 1 , 108) and Fig. 8B is a cross-sectional view of the input port cap (Fig. 1 , 108). As depicted in Fig. 8A and 8B, the protrusions (638) coupled the trigger (114) align with the trigger (114). Aligning the trigger (114) with the protrusions (638) may reduce the force to open the lid (110). Fig. 8A also clearly depicts the spring (216) as being integrated with the input port cap (Fig. 1 , 108) components.

[0081] Figs. 9A - 9C are views of a vent plug (532), according to an example of the principles described herein. The vent plug (532) may be formed of a plastic material. In this example, the vent plug (532) may be press fit into the lid (110). In another example, the vent plug (532) may be formed of a deformable elastomer material that deforms in the presence of pressure. Accordingly, as the lid (110) is positioned over the input port (104) and the retention mechanism (Fig. 1 , 112) is engaged to close the lid (110), the vent plug (532) may seal the input port (104) such that fluid does not escape the mixing chamber (Fig. 1 , 102). In some examples, the vent plug (532) includes a labyrinth race (940) to reduce humidity transfer. That is, if humidity were allowed to enter the mixing chamber (102), it may skew the results of analysis and effect the operations that are carried out in the mixing chamber (102). Accordingly, the labyrinth race (940) reduces such humidity transfer between the environment and the interior volume of the mixing chamber (102). [0082] Fig. 10 is a flow chart of a method (1000) of sealing a sample preparation device (Fig. 1 , 100), according to an example of the principles described herein. As described above, sample preparation may include lysing a sample and binding the sample to magnetic microparticles or facilitating an interaction between the sample and a reagent. Prior to such an interaction, the sample is introduced to the mixing chamber (Fig. 1 , 102). During use however, and prior to use, it may be desirable to seal the mixing chamber (Fig. 1 , 102) to prevent environmental contaminants or debris from entering the mixing chamber (Fig. 1 , 102) and to prevent any contents stored therein, such as a dry or liquid reagent and/or magnetic microparticles , from escaping. Accordingly, the input port (Fig. 1 , 104) of the sample preparation device (Fig. 1 , 100) is covered (block 1001 ) with an input port cap (Fig. 1 , 108).

[0083] Via a first contact surface on the input port cap (Fig. 1 , 108), the input port cap (Fig. 1 , 108) is opened (block 1002) to expose the mixing chamber (Fig. 1 , 102) to a sample input device such as a pipette. Note that the opening may be via manual or automatic activation of the first contact surface. This first contact surface may be used exclusively for opening the lid (Fig. 1 , 110) whereas a separate contact surface is used to close the lid (Fig. 1 , 110). Opening (block 1002) the input port cap (Fig. 1 , 108) may include rotating the input port cap (Fig. 1 , 108) more than 90 degrees from its closed position. This degree of rotation may be provided by the spring (Fig. 2, 216). Doing so may allow a user to insert a pipette into the input port (Fig. 1 , 104) without additional user manipulation. That is, a user may avoid touching the lid (Fig. 1 , 110) to have it open further, and the spring (Fig. 2, 216) may by its own action open (block 1002) the lid (Fig. 1 , 110) to a degree such that a user need not contact the lid (Fig. 1 , 110) to open it further.

[0084] After the sample has been inserted into the mixing chamber (Fig. 1 , 102), the input port cap (Fig. 1 , 108) may be closed (block 1003) via a different surface than that used to open the lid (Fig. 1 , 110). That is, via activation at a second contact surface, which may be the lid (Fig. 1 , 110), the input port cap (Fig. 1 , 108) may be closed to seal the contents inside the mixing chamber (Fig.

1 , 102). Thus, the present method (100) provides for the opening and closing of an input port (Fig. 1 , 104) all while reducing the likelihood of crosscontamination of the sample.

[0085] In summary, such a sample preparation device 1) provides two separate surfaces for opening and closing of the lid to reduce the likelihood of cross-contamination of samples, 2) upon unlatching, opens to a given angle, providing visual feedback to the user that the sample input port is ready to receive sample, 3) reduces the number of components, thereby reducing the consumable waste stream, 4) provides the same consistent press action, against the consumable, for both opening and closing of the sample input cap; and 5) simplifies assembly operations. However, the devices disclosed herein may address other matters and deficiencies in a number of technical areas.