Microcapillary loader

Abstract

A system is described that can be used for loading a microcapillary array chip for use with a high-throughput analysis system. The system may include a reservoir and a base for holding a microcapillary array chip in place while loading liquid from the reservoir to microcapillaries of the microcapillary array chip by translating the reservoir across the microcapillary array chip. Samples, reagents, and the like can be loaded into the microcapillary array chip using the system. A hydrating gel can be applied to the microcapillary chip to allow for more complicated microcapillary loading schemes.

Description

OMAB2015WO PATENT MICROCAPILLARY LOADERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U. S. Provisional Application No.63 / 743,862, filed January 10, 2025, and U. S. Provisional Application No. 63 / 907,628, filed October 29, 2025, the content of each of which is incorporated by reference in its entirety.BACKGROUNDField

[0002] The present disclosure relates to high-throughput biological screening and related devices.Description of the Related Art

[0003] The analysis of biological samples, including the identification, characterization, and re-engineering of proteins, nucleic acids, carbohydrates, and other important biomolecules, has benefited greatly from the scaling up of sample numbers and the scaling down of sample sizes. For example, the two-dimensional microarrays of biological materials, such as DNA microarrays, have enabled the development of high-throughput screening methods involving multiplexed approaches for processing samples and detecting results,

[0004] The above approaches have, in some cases, benefited from their combination with optical sensing technology to identify specimens of interest using fluorescent or other corresponding specific and sensitive labeling approaches.

[0005] While such techniques provide analytical information about a particular sample, for example the presence and potentially the amount of a particular biomolecule in a solution or the sequence of a particular nucleic acid or polypeptide, they typically do not allow for the recovery of a biological sample identified by the assay without inactivating or otherwise damaging the sample of interest.

[0006] Microcapillary arrays provide a platform that permit high-throughput screening while allowing for the recovery of a biological sample. However, there is a continuing need to develop improved microscale screening and analysis methods and systems with high throughput capabilities.SUMMARY

[0007] An aspect of the present disclosure relates to a system for loading a microcapillary array with a liquid. The system can include: a base that can receive a microcapillary array chip; a reservoir that can receive a liquid and that is translatably coupled to the base, the reservoir including a first fluid opening. When the microcapillary array chip is positioned in the base, the reservoir and first fluid opening can translate relative to the base and the microcapillary array chip parallel to a top surface of the microcapillary array chip.

[0008] In some examples, the base includes one or more rail, the reservoir coupled to the one or more rail, wherein the one or more rail can allow the reservoir to slide relative along a horizontal plane of the base. In further examples, the base includes two rails, the two rails that can allow the reservoir to slide along the horizontal plane of the base. In yet further examples, a first of the two rails is positioned on a first side of the base, and a second of the two rails is positioned on a second side of the base, the second side of the base opposing the first side of the base,

[0009] In some examples base including a depression, the depression that can receive the microcapillary array chip. In some examples, the system includes a reservoir tray translatably coupled to the base, the reservoir tray that can receive the reservoir. In some further examples, the reservoir tray can manually slide. In yet further examples, the reservoir tray includes a handle. The handle can be rotatable to allow a user to pull the reservoir tray in two opposite directions. In alternate examples, a motor can move the reservoir tray relative to the base. In some examples, the reservoir is detachable from the reservoir tray. In some examples, the reservoir tray includes at least one lock that can secure the reservoir within the reservoir tray. In some examples, the reservoir tray includes a rectangular frame that can receive the reservoir. In some examples, the reservoir tray includes two sides that can receive the reservoir. In some examples, the reservoir tray includes a first side aperture that can slidingly receive a first rail of the base and a second side aperture that can slidingly receive and a second rail of the base.

[0010] In some examples, the system includes a chip holder to hold the microcapillary array chip. In such examples, the base can receive the chip holder. In further examples, the base includes a depression that can receive the chip holder. In yet further examples, sides of the depression can made with sides of the chip holder, and the sides of thedepression can prevent lateral movement of the chip holder relative to the base. In some examples, the chip holder can be placed in an analysis device. In some examples, the base can include an opening where, when the microcapillary array chip is positioned in the chip holder and the chip holder is positioned on the base, at least a portion of the microcapillary array chip is positioned above the opening.

[0011] In some examples, the reservoir can contact a top surface of the microcapillary array chip when the microcapillary array chip is positioned for liquid loading. In some examples, the reservoir can receive 1-3 mL of liquid. In some examples, the first fluid opening can run at least a majority of a length of the reservoir. In some examples, the first fluid opening can extend longitudinal to the reservoir. In some examples, the first fluid opening includes a width of about 0.5 to about 1,0 mm. In further examples, the width of the first fluid opening is about 0.8 to about 0.9 mm. In some examples, the first fluid opening includes a length about of 35 to about 50 mm. In further examples, the length of the first fluid opening is about 40 to about 45 mm. In some examples, the reservoir includes a height about 10 mm or more. In some examples, the reservoir includes a first end, an opposite second end, a first side, and a second side opposite the first side, wherein the first end includes a second fluid opening and the second end includes the first fluid opening, wherein the first side and second side taper from the first end to the second end. In some examples, the reservoir is symmetrical about the first fluid opening. In some examples, the reservoir comprises two or more trough portions, wherein each trough portion is configured to separately receive liquid, and wherein each trough portion comprises a separate fluid opening.

[0012] In some examples, the system includes the microcapillary array chip. In further examples, the reservoir is dimensioned such that the hydrostatic pressure exerted on the microcapillaries of the microcapillary array chip from loaded liquid via the first fluid opening does not exceed a capillary force in the microcapillaries.

[0013] In some examples, the liquid includes a cell sample. In some examples, the liquid includes a reagent.

[0014] In another aspect, the present disclosure provides for a method of loading a microcapillary array chip. The method includes: introducing liquid to a reservoir; and sliding the reservoir across a first surface of the microcapillary array chip from a first end of the microcapillary array chip to a second end of the microcapillary array chip, wherein the slidingof the reservoir allows the liquid to transfer from the reservoir to microcapillaries of the microcapillary array chip.

[0015] In some examples, the method includes positioning a reservoir in a reservoir tray. In some further examples, the method includes positioning a microcapillary array chip in a base, wherein the base is translatably coupled to the reservoir tray. In some further examples, positioning the microcapillary array chip includes positioning the microcapillary’ array chip in a chip holder and positioning the chip holder in the base, where the chip holder can hold the microcapillary array chip and mate with the base.

[0016] In some examples, the method includes adding about 1 to about 3 ml. of liquid to the reservoir. In some examples, the liquid includes a cell sample. In some examples, the method includes placing, after transferring liquid to the microcapillaries of the microcapillary array chip, the microcapillary array chip in an analysis device. In some examples, the method includes positioning the reservoir at a first position, wherein, at the first position, the reservoir contacts the microcapillary array chip at the first end. In some examples, the sliding is conducted by pushing or pulling a handle, the handle coupled the reservoir. In some examples, the sliding includes translating the reservoir along one or more rails. In some examples, the method includes applying a hydration gel to the first surface.

[0017] In another aspect, the present disclosure provides for a method of loading a microcapillary array chip. The method can include: loading a first fluid into a plurality of microcapillaries of a microcapillary chip via openings in a first surface of the microcapillary chip; and loading a second fluid into the plurality of microcapillaries via openings in a second surface of the microcapillary chip, the second surface opposite the first surface.

[0018] In some examples, the method includes screening the microcapillary chip. Some examples include applying a hydration gel to a first surface of the microcapillary chip after loading the first fluid into the plurality of microcapillaries. In some examples, the hydration gel comprises a hydrogel. In some examples, the hydration gel comprises an agarose. In some examples, the agarose is a 1% agarose or 2% agarose. In some examples, during the step of screening, the hydration gel remains applied to the microcapillary’ chip. In further examples, the screening further includes: imaging the microcapillary chip to determine at least one microcapillary of interest; and isolating contents of at the least one microcapillaryof interest. The method can include incubating, after the loading the first fluid and before loading the second fluid, the microcapillary chip

[0019] In some examples, the first fluid comprises first cells. In further examples, the first cells include prokaryotic cells. In yet further examples, the first cells include bacteria cells. In even yet further examples, the first cells include E. coli cells. In other examples, the first cells include eukaryotic cells. In some further examples, the first cells include B cells. In some examples, the second fluid includes any one or more of assay reagents, wash buffer, or second cells. In some examples, the second cells include reporter cells. In some examples, the second cells include T cells.

[0020] In some examples, the loading the first fluid or the loading the second fluid comprises the steps of loading a microcapillary chip by sliding a reservoir across a surface of the microcapillary chip in accordance with the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIGS. 1A--1C schematically illustrate the steps of an exemplary microcapillary screening assay. The illustration on the left in each panel is a cross-sectional view from the side of a single microcapillary. The illustration on the right in each panel is a bottom view of a subsection of the array of microcapillaries. The shading in each case is intended to illustrate an electromagnetic signal, such as fluorescence.

[0022] FIGS. 2A-2E are different views of a microscope system designed to carry out the screening methods of the instant disclosure.

[0023] FIG. 3A illustrates an exemplary screening array stage.

[0024] FIG. 3B illustrates an exemplary recovery array stage.

[0025] FIG. 4 shows exemplary positioning of a screening array and a recovery array relative to one another during the recovery of three samples of interest from the screening array, as facilitated by the instant sample recovery systems.

[0026] FIG. 5A illustrates an isometric perspective view of a microcapillary loader.

[0027] FIG. 5B illustrates a top-down view of the microcapillary loader of FIG. 5 A

[0028] FIG. 6A illustrates an isometric perspective view of a reservoir.

[0029] FIG. 6B illustrates a top-down view of the reservoir of FIG. 6A.

[0030] FIG. 6C illustrates a side view of the reservoir of FIG. 6A.

[0031] FIG. 6D illustrates a cross-sectional side view of the reservoir of FIG. 6 A.

[0032] FIG. 7 A illustrates an isometric perspective view of a microcapillary array chip.

[0033] FIG. 7B illustrates a top-down perspective view of the microcapillary array chip of FIG. 7 A.

[0034] FIG. 8A illustrates an isometric perspective view of a chip holder that can hold the chip shown in FIGS. 7A-7B.

[0035] FIG. 8B illustrates a top-down view of the hip holder of FIG, 8 A.

[0036] FIG, 9 A illustrates a loader base as initially depicted in FIGS, 5A-5B.

[0037] FIG. 9B illustrates a top-down view of the loader base of FIG. 9A.

[0038] FIG, 10A illustrates a flow diagram of a method of using a microcapillary loader.

[0039] FIG, 10B includes photographs of a process of using the microcapillary loader.

[0040] FIG. 11 is a cross-sectional side view of the loader indicating movement of liquid and components of the loader when loading the microcapillary array chip.

[0041] FIGS. 12A-12C illustrate a process of partially loading a microcapillary chip using a divided reservoir.

[0042] FIG. 13A illustrates a method of reverse chip loading.

[0043] FIG. 13B includes a series of schematic drawings to accompany the method depicted in FIG. 13A.

[0044] FIGS. 14A-14C are images of a microcapillary array chip having been loaded using a microcapillary loader.

[0045] FIG. 15 is an image of a microcapillary array chip subjected to a reverse chip loading method.DETAILED DESCRIPTION

[0046] In high-throughput systems such as the one discussed herein, there is a need to uniformly load a microcapillary array with liquid. In various examples, the liquid can contain the samples (e.g., cell and / or variant protein samples) to be analyzed, for example by the high-throughput system.Overview of High-Throughput System

[0047] Microcapillary arrays have recently been employed in approaches for high- throughput analysis and protein engineering with large numbers of biological samples, for example in an approach that has been termed “microcapillary single-cell analysis and laser extraction” or “pSCALE”. See Chen et al. (2016) Nature Chem. Biol. 12:76-81; DOI: 10.1038 / NCHEMBI0.1978; see also US Pub. Nos. 2022 / 0162594, 2022 / 0373440, 2020 / 0080075, 2018 / 0188276 (each reference incorporated herein in its entirety). This approach relies on the spatial segregation of single cells within a microcapillary array, and thus enables repeated imaging, cell growth, and protein expression of the separate samples within each microcapillary of the microcapillary array. Accordingly, the technique enables massively parallel, quantitative biochemical and biophysical measurements on millions or multi-millions of samples within a microcapillary array, for example, in the analysis of millions or multi¬ millions of protein variants expressed from yeast, bacteria, rodent, human, chicken, or other suitable cells distributed throughout the array. Advantageously, the approach allows for the simultaneous time-resolved kinetic analysis of the multiplexed samples, as well as the sorting of those cells based on targeted phenotypic features.

[0048] FIGS. 1A-1C illustrate an exemplary screening method for a soluble protein capable of associating with a cell-surface protein (e.g., the epidermal growth factor receptor (“EGFR”)) as an immobilized target molecule, in this case an immobilized target protein within a microcapillary of a pSCALE system. FIG. 1 A (left panel) shows the target cell, which expresses the protein on its surface. Also shown is a “library expressing cell”, which expresses a population of variant proteins (e.g., antibodies), and a number of fluorescent detection antibodies in the microcapillary solution. A bottom view of the microcapillary array is illustrated in the right panel. It is to be understood that other assays may be suitably implemented on the high-throughput system and that description of FIGS. 1A-1C is not intended to limit the assays which can be performed on the high-throughput system.

[0049] Each capillary can include cells secreting the variant protein of interest (the “library expressing cell”), a target protein immobilized on a surface, a reporter element, and a reaction buffer. The variant protein of interest can be a member of a population of variant proteins, i.e., a protein library. In some examples, the target protein may be immobilized on the surface of a cell. The target protein can be a native, cell-surface receptor (e.g., EGFR).-1-Alternatively, the target protein could be immobilized on another surface, such as a bead surface or an interior surface of the microcapillary itself. The reporter element may include a fluorescently-labeled antibody specific for the secreted protein (e.g., the “fluorescent detection antibodies”). The antibody can specifically localize to an epitope on the secreted protein but ideally does not interfere with the binding of the secreted protein to the target protein on the target cell. Alternatively, the reporter element can be a signaling pathway within the cells that express the target protein. If a secreted variant protein binds the target protein on the cell surface and activates the signaling pathway within the target cell, the binding interaction will generate a fluorescent signal within the cell. The reaction buffer can be media for the library-expressing cells or for the target cells. The reaction buffer may additionally or alternatively be a mammalian imaging solution.

[0050] FIG. 1A illustrates the addition of the above-discussed components to a microcapillary, FIG. IB illustrates expression of a specific “secreted protein” by the libraryexpressing cell into the microcapillary. Secreted protein variants capable of binding to the target protein (e.g., antibodies) can be localized to the target cell surface. FIG. 1C illustrates association of fluorescent detection antibodies associated with the bound secreted protein variants. Such association can indicate which microcapillary contains a sample of interest.

[0051] In some of the method embodiments, for example in the screening methods illustrated in FIGS. 1 A--1C, the variant protein mediates the association of a reporter element with a target molecule, in this example, a target molecule on the surface of a target cell. As shown in FIG. IB, where the variant protein (here designated as a “secreted protein”) has sufficient affinity for its target molecule on the target cell that the variant proteins associate with the target cell under the conditions of the microcapillary solution. The reporter element (here designated as “fluorescent detection antibodies”) binds to the variant protein, ideally at an epitope that does not affect the affinity of the variant protein for the target molecule, as shown in FIG. 1C.

[0052] In other embodiments, the reporter element is an intracellular reporter element that generates a detectable signal in connection with a binding event, such as, for example, the association of a variant protein with an immobilized target molecule, for example, a receptor or other target molecule on the surface of the cell. In these embodiments, the reporter element may include an entire cellular pathway, such as, for example, an intracellular signalingpathway. Such a pathway should include, or be engineered to include, a detectable signal as the downstream readout of the pathway. In contrast to the assays illustrated in FIGS. 1A-1C, where the detectable signal is bound to the outer surface of the target cell, the detectable signal in these embodiments would typically be generated inside the target cell.

[0053] Various views of an exemplary’ system capable of performing the steps laid out in FIGS. 1A-1C and then recovering samples of interest are provided in FIGS. 2A-2E. In particular, FIG. 2E illustrates an exploded view of a screening array stage 12, a recovery array 14, a recovery array holder 16, a first recovery / array stage 18, a second recovery array stage 20, and a microscope objective 22. The optical pathways of an extraction beam, in this case a laser beam, and of the screening array image, are illustrated from the three perspectives shown in FIGS. 2B 2D as “laser beam path” and “imaging path”, respectively. The screening array stage is preferably configured to accommodate an array of microscale sample vessels (e.g., microcapillary array) within an aperture that allows for the transmission of the optical beams through the associated array. An example screening stage is shown in more detail in FIG. 3A. An exemplary recovery array stage is illustrated in FIG. 3B. At least one recovery array stage is preferably connected to a recovery array holder, for example as illustrated in FIG. 2E, to facilitate the reversible association of the recovery array (e.g., a multi-well collection plate as described herein) with the recovery array stage. Reversible association refers to the ability of the recovery array to be able to associate and dissociate with the recovery array stage (e.g., a first recovery stage) before, during, or after the sample recovery process. In some embodiments, reversible association indicates that the recovery array can be placed into the system and / or removed from the system, in some cases more than once. In some embodiments, the recovery array is reversibly associated with the recovery array stage via spring tension, gravity, magnetic forces, friction, screws / fasteners, and / or Velcro.

[0054] In preferred embodiments, the multi-stage sample recovery systems include both a screening array reversibly associated with the screening array stage and a recovery array reversibly associated with the first recovery array stage. More specifically, the screening array includes a plurality of microscale sample vessels, and the recovery array includes a plurality of recovery vessels (e.g., wells in a multi- well plate).

[0055] As previously noted, the instant multi-stage sample recovery systems typically include an optical source and an optical detector to identify samples of interest withina screening array. In some cases, for example where a bioluminescent signal is being monitored, a separate optical source may not be required, and the systems may include only an optical detector. In either case, the optical detector is typically configured to monitor optical signals emitted from samples in a screening array by optically coupling the screening array to the detector through an aperture in the screening array stage. As described above, observation of optical signals from reporter elements within the sample vessels of the screening array enables the identification of specific sample vessels holding samples of interest, and the contents of those sample vessels can then be recovered by a pulse from the extraction beam generator. The optical detector, for example an imaging camera such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) imaging sensor, is ideally capable of imaging large numbers of sample vessels from the screening array within a single field. In some embodiments, the optical detector is a charge-coupled device (CCD). In some embodiments, the optical detector is complementary metal-oxide-semiconductor (CMOS) imaging sensor. In some embodiments, the optical detector is a photodiode. Where fluorescent labels are used in the reporter elements, imaging detectors are typically chosen for their sensitivity in the visible range of the electromagnetic spectrum. Fluorescence emission from the screening array is directed to the optical detector, typically through a microscope objective, via the imaging path of the system. Commercial microscopes, such as, for example, Nikon Eclipse series inverted microscopes and the like, can be suitably adapted for use in the instant systems, as would be understood by those of ordinary skill in the art.

[0056] In some embodiments, the multi-stage sample recovery systems further include an extraction beam generator optically coupled through an aperture in the screening array stage to one microscale sample vessel within the screening array. More specifically, the extraction beam can be a laser beam, for example a beam emitted by a diode laser, a diode- pumped Q-switched laser, such as a diode- pumped Q-switched Nd: YLF laser, or another appropriate laser device. In some embodiments, the laser is a diode laser. In some embodiments, the laser is a nanosecond pulsed laser. In some embodiments, the laser is a picosecond pulsed laser. Where the system includes an array of microcapillaries, the extraction beam can be directed at the water-glass interface between the microcapillary wall and the sample contained in the microcapillary. Use of lasers to isolate the contents of specific microcapillaries identified by fluorescence imaging within an array of microcapillaries hasbeen described previously. See, e.g., Chen et al. (2016) Nature Chem. Biol. 12:76-81; DOI: 10.1038 / NCHEMBIO 1978 and U. S. Patent Application Publication No. 2016 / 0244749 Al, which are incorporated herein by reference in their entirety.

[0057] In some embodiments, the extraction beam is directed from below the targeted microscale sample vessel. It should also be understood, however, that the extraction beam can alternatively be directed from above the targeted microscale sample vessel if so desired.

[0058] In specific embodiments, the system further includes a second recovery array stage. The first and second recovery array stages can reside in a horizontal plane. In more specific embodiments, the second recovery array stage can be oriented orthogonally to the first recovery array stage while still in the horizontal plane. According to these embodiments, samples can be recovered automatically from a screening array into a recovery array having recovery vessels arranged in orderly grids, in particular grids with x rows and y columns, where x and y can independently be 3, 8, 10, 12, 30, 100, or even more, or a value within a range defined by any two of the previous values.

[0059] In some embodiments, the screening array stage and the recovery array stage or stages are controllable by one or more electronic motors as would be understood by those of ordinary skill in the art.

[0060] In some embodiments, the screening array and the recovery array of the instant systems are configured so that at least one microscale sample vessel (e.g., a microcapillary array) and at least one recovery vessel (e.g., a collection plate in accordance with the present disclosure) are positioned within a working distance of the microscope objective. In some embodiments, the working distance of the microscope objective is from about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 mm, or within a range defined by any two of the proceeding values, though in some examples other values may be suitably implemented. In some embodiments, the working distance, including the vertical distance, is from about 1 mm to 40 mm. In some embodiments, the working distance, including the vertical distance, is from about 2 mm to 30 mm. In some embodiments, the working distance, including the vertical distance, is from about 1.5 mm to 30 mm. In some embodiments, the working distance, including the vertical distance, is from about 2.5 mm to 30 mm. In someembodiments, the working distance, including the vertical distance, is from about 2 mm to 25 mm. In some embodiments, the working distance, including the vertical distance, is from about 3 mm to 30 mm. In some embodiments, the working distance, including the vertical distance, is from about 3 mm to 25 mm. More specifically, the working distance is from about 2.5 mm to about 25 mm. In these embodiments, the systems allow for the simultaneous imaging of the contents of a microscale sample vessel of interest and the associated recovery vessel. In more specific embodiments, the working distance of the microscope objective is from about 4 mm to about 10 mm or even from about 6 mm to about 8 mm, for example about 7,4 mm. In some embodiments, the recovery array is a first recovery array. In some embodiments, the recovery array is a second recovery array.

[0061] As previously noted, in preferred embodiments the screening arrays of the instant multi-stage sample recovery systems include a plurality of microcapillaries. More specifically, the screening arrays include at least 100,000, at least 300,000, at least 1,000,000, at least 3,000,000, at least 10,000,000, or even more microcapillaries. In some embodiments, the array includes at least 100,000, at least 200,000, at least 300,000, at least 400,000, at least 500,000, at least 600,000, at least 700,000, at least 800,000, at least 1,000,000, at least 1,500,000, at least 2,000,000, at least 2,500,000, or at least 3,000,000 or more microcapillaries.

[0062] As also previously noted, in some examples the recovery arrays of the instant multi-stage sample recovery systems can include one or more recovery vessels (e.g., collection plates in accordance with the present disclosure). Accordingly, in such systems, the recovery arrays may include at least 1 recovery vessel, at least 2 recovery vessels, at least 3 recovery vessels, at least 10 recovery vessels, at least 30 recovery vessels, at least 100 recovery vessels, or even more recovery vessels.

[0063] In preferred embodiments, the recovery array of the instant systems is positioned below the screening array. In some embodiments, the recovery array and the screening array are at least 25 mm, at least 30 mm, at least 35 mm, at least 40 mm, at least 45 mm, or at least 50 mm or more apart. In some embodiments, the recovery array and the screening array are at least 30 mm, at least 35 mm, or at least 40 mm apart. In some embodiments, the recovery array and the screening array are at least at least 35 mm or at least 40 mm apart. In some embodiments, the recovery array and the screening array are at least at least 35 mm apart. In some embodiments, the recovery array is at least 25 mm, at least 30 mm,at least 35 mm, at least 40 mm, at least 45 mm, or at least 50 mm below the screening array. In some embodiments, the recovery array is at least 30 mm, at least 35 mm, or at least 40 mm below the screening array. In some embodiments, the recovery array is at least 35 mm or at least 40 mm below the screening array. In some embodiments, the recovery’ array is at least 35 mm below the screening array.

[0064] It will be readily apparent to one of ordinary skill in the relevant arts that other suitable modifications and adaptations to the methods and applications described herein can be made without departing from the scope of the invention or any embodiment thereof. Having now described the present invention m detail, the same will be more clearly understood by reference to the following Examples, which are included herewith for purposes of illustration only and are not intended to be limiting of the invention.

[0065] As noted above, the sample recovery7system consists of an X-Y stage, as illustrated in FIG. 3A, and at least one X / Y stage, as illustrated in FIG. 3B, The stages interface with a Nikon Ti-E Motorized microscope or the like. The X-Y stage holds a screening array, such as an array of microcapillaries, and X / Y stage or stages are configured to hold a sample recovery array, such as 96-well plate or the like.

[0066] Light from the associated microscope travels through both tiers of stages for purposes of visualizing the contents of each sample in the screening array, for example each microcapillary in an array of microcapillaries held on the screening array stage. Because of the close proximity between the screening array stage and the recovery array stage, the objective is also able to image vessels associated with the recovery array, for example an 18-well slide.

[0067] These stages work independently of one another to position the desired microscale sample vessel, for example a microcapillary within an array of microcapillaries, and the desired capture surface, for example a recovery vessel within a recovery array, at the desired location relative to the microscope objective. For example, as illustrated in FIG. 4, if screening array 10 is found to contain three sample vessels of interest, for example the three sample vessels labeled 1, 2, and 3 in the drawing, the screening array stage is moved to position the first sample vessel in line with the light path of the extraction beam, and the recovery array stage is likewise independently moved to position the first recovery vessel of recovery array 14 in line with the light paths as shown in the top left panel of FIG. 4.

[0068] After the first sample of interest has been transferred into the first recovery vessel, the screening array stage is moved m the X and Y directions to position the second sample of interest in line with the extraction beam, and the recovery array stage is independently moved to position the second recovery vessel in line with the beam, as shown in the top right panel of FIG. 4. After the second sample of interest has been transferred into the second recovery’ vessel, the process is repeated by moving the screening array stage in the X and Y directions as necessary to position the third sample of interest in line with the extraction beam. The recovery stage is independently moved to position the third recovery vessel in line with the beam, as shown in the bottom panel of FIG. 4, and the sample is transferred into the third recovery vessel by the extraction beam.Overview of Microcapillary Loader

[0069] In some examples, a microcapillary loader can be used to load a microcapillary array discussed with reference to the method of FIGS. 1A-1C and the system of FIGS. 2A-6E.

[0070] FIGS. 5 A and 5B illustrate views of a microcapillary loader 500 holding a microcapillary array chip 504. The microcapillary loader 500 can include a chip holder 502, a reservoir 506 (also referred to herein as a reagent reservoir), a base portion 508, a reservoir tray 510, rails 512a and 512b, and a handle 514. The microcapillary array chip 504 can be positioned within the chip holder 502. The chip holder 502 can in turn be positioned within the base portion 508. The reservoir tray 510 can be translatably coupled to the base portion 508, In some examples, the reservoir tray 510 can slide along the rails 512a and 512b, such that the reservoir tray 510 translates relative to the base portion 508. The reservoir 506 can sit within the reservoir tray 510. Movement of the reservoir tray 510 relative to the base portion 508 can move the reservoir 506 when the reservoir 506 is positioned within the reservoir tray 510. The handle 514 can be coupled to the reservoir tray 510. A user can pull the handle 514 to move the reservoir tray 510 relative to the base portion 508. The reservoir 506 can be detachable from the reservoir tray 510. As the reservoir tray 510 is moved, liquid may move from the reservoir 506 to microcapillaries of the microcapillary array chip 504.Reservoir

[0071] FIGS. 6A-6D illustrate an isometric perspective view of the reservoir 506. The reservoir 506 can include a top surface 602, a lip 604, a trough portion 606, a fluid opening 608, an overhang 614, a bottom surface 616, a top fluid opening 620, a first end 622, a second end 624, a first side 626, and a second side 628. When positioned in the reservoir tray 510, liquid can be loaded into the trough portion 606. The liquid introduced to the reservoir 506 may include a sample, one or more reagents, and / or the like. Such samples may include, for example.

[0072] The fluid opening 608 can include a width 610 and a length 612. In some embodiments, the fluid opening 608 is longitudinal in shape, with a length 612 longer than its width 610. In some embodiments, the fluid opening 608 is generally rectangular in shape. In some embodiments, the fluid opening 608 may include rounded corners. In some embodiments, the fluid opening 608 is a slot in the bottom of the reservoir 506. The length 612 of the fluid opening 608 can run at least a majority of an overall length of the reservoir 506. The length 612 may be at least as long as a width of the microcapillary array of the microcapillary array chip 504. In such examples, the fluid opening 608 is able to cover all of the microcapillaries of the microcapillary array when the reservoir 506 slides across the top surface of the microcapillary array chip. The length 612 may be about 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60 mm, or within a range defined by any two of the previous values, though m some instances other values may be suitably implemented. In some examples, the length 612 is about 35 to about 50 mm. In some examples, the length 612 is about 40 to about 45 mm. In some examples, the length 612 is about 42 to about 44 mm. In some examples, the length 612 is about 42 mm or about 43 mm.

[0073] The width 610 of the fluid opening 608 can be sufficiently large to allow fluid from the trough portion 606 to flow to the microcapillaries of the microcapillary array chip 504 when the microcapillary loader 500 is in use. The width 610 may be narrow enough that surface tension is sufficient to hold the loaded liquid inside the reservoir 506 when no microcapillaries are positioned underneath the fluid opening 608. The width 610 can be about 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 mm, or within a range defined by any two of the previous values, though in some instances other values maybe suitably implemented. In some examples, the width 610 may about 0.5 mm to about 1.0 mm. In some examples, the width 610 may be about 0.8 mm to about 0.9 mm.

[0074] The lip 604 and / or the overhang 614 can be adapted to rest on and / or couple to the reservoir tray sides 906, with reference to FIGS. 9A and 9B. The lip 604 and / or the overhang 614 can be sized and / or shaped to ensure a fit with the reservoir tray sides 906 so as to prevent or inhibit movement of the reservoir 506 relative to the reservoir tray 510.

[0075] The bottom surface 616 of the reservoir 506 can contact a top surface of the microcapillary array chip when the microcapillary array chip, the chip holder, and the reservoir tray are positioned for liquid loading.

[0076] The trough portion 606 of the reservoir 506 may be sized to be able to receive at least about 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0,6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1,8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 mL of liquid, or within a range defined by any two of the previous values, though in some instances other values may be suitably implemented. In some examples, the trough portion 606 is sized to receive 1 -3 mL of liquid.

[0077] The reservoir 506 can include a height 618. The magnitude of the height 618 may affect the fluid pressure exerted at the fluid opening 608 when the trough portion 606 is filled with liquid. In some examples, the height 618 can be 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11.0, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13.0, 13.1, 13.2, 13.3, 13.4, 13.5, 13.6, 13.7, 13.8, 13.9, 14.0, 14.1, 14.2, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14.9, 15.0, 15.1, 15.2, 15.3, 15.4, 15.5, 15.6, 15.7, 15.8, 15.9, or 16.0 mm, or within a range defined by any two of the previous values, though m some instances other values may be suitably implemented. In some examples, the height 618 is about 10 mm or more. The height 618 of the reservoir 506 may allow for the bottom surface 616 of the reservoir 506 to contact (or nearly contact) the top surface of the microcapillary array chip 504 when the reservoir 506 and microcapillary array chip 504 are positioned in the loader. In some examples, the bottomsurface 616 of the reservoir 506 can create a fluid-tight seal with the top 702 of the microcapillary array chip 504. Such a fluid-tight seal between the bottom surface 616 and the top 702 can ensure that fluid for loading only travels through the fluid opening 608 to microcapillaries immediately below’ the fluid opening 608.

[0078] A first end 622 of the reservoir 506 can include a top fluid opening 620. A second end 624 can include the fluid opening 608. An interior surface of the trough portion 606 may taper from the first end 622 to the second end 624. The first side 626 and second side 628 of the reservoir 506 may taper from the first end 622 to the 624. The reservoir 506 can be symmetrical about a central vertical plane defined at least in part by a center of the fluid opening 608. The tapered shape of the interior surface of the trough portion 606, the first side 626 and second side 628, and / or the reservoir 506 as a whole can assist m providing enough pressure to the fluid opening 608 to load fluid into a microcapillary array chip. For example, the tapered shape allows most of the volume of the loaded liquid to be at the top of the trough portion 606. Therefore, the height of the liquid within the trough portion 606 (and hence the hydrostatic pressure of the liquid) can stay largely unchanged while liquid is dispensed to the microcapillary array chip 504. The overall height 618 of the reservoir 506 coupled with other structural features of the reservoir 506 can ensure that there is enough pressure, when the reservoir 506 is loaded with liquid, to aid in pushing the liquid into the microcapillaries of the microcapillary array chip 504. The capillary wicking force of the microcapillary array chip 504 may also be a consideration for the shape and / or dimensions of the microcapillary array chip 504. If the capillary forces of the microcapillary array chip 504 are relatively' high, the height 618 of the reservoir 506 may be small to create adequate hydrostatic pressure of the liquid to ensure loading of liquid into the microcapillaries. On the other hand, if the capillary wicking force of the microcapillary array chip 504 are relatively low, the height 618 of the reservoir 506 may be large to create adequate hydrostatic pressure to ensure loading of liquid into the microcapillaries. Additionally, the height 618 should not be so great that, when loaded with fluid, there is too much hydrostatic pressure. An excess of hydrostatic pressure of liquid in the reservoir 506 may cause fluid to flow out the bottom of the microcapillary array chip 504, which is undesirable.

[0079] In alternative examples, the reservoir can be integrated into a microcapillary loader base (e.g., integrated with the reservoir tray 510). That is to say, the reservoir may not be removable from the microcapillary loader base.Microcapillary Array Chip and Chip Holder

[0080] A microcapillary array chip can be used in the high-throughput screening system discussed herein. FIGS. 7A and 7B illustrate views of a microcapillary array chip 504. The microcapillary array chip 504 includes a top 702, and a bottom 704. The microcapillary array chip 504 can include a plurality of microcapillaries. The microcapillary array may include an array of microcapillaries. The microcapillary array may include hundreds, thousands, tens of thousands, hundreds of thousands, millions, or tens of millions of microcapillaries. Each of the microcapillaries of the microcapillary array can extend from the top 702 to the bottom 704 of the chip. That is to say, each of the microcapillaries of the microcapillary array is a through-hole. The microcapillary array chip 504 can be loaded into a screening system as discussed with reference to FIGS. 1A-2E. The microcapillaries may be able to receive fluid. In some examples, the microcapillaries may be able to exert a wicking force (also referred to herein as capillary wicking force) on a fluid introduced to the top surface 702 to pull the fluid into an internal volume of the microcapillaries. In some examples, an interior surface of each of the microcapillaries is a wetting surface. The capillary wicking force may be affected by the dimensions of the microcapillaries and the wetting properties of the interior and exterior surfaces of the microcapillaries. The magnitude of the capillary wicking force can influence design choices with respect to the hydrostatic pressure of liquid of the reservoir 506, as discussed above. It may be desirable that the hydrostatic pressure exerted by the liquid in the reservoir 506 does not exceed the capillary wicking force of the microcapillaries so as to prevent and / or inhibit leakage from the bottom 704 of the microcapillary array chip 504. The magnitude of the capillary' wicking force may also be tuned (e.g., increased) to minimize and / or prevent leakage of fluid from the bottom 704 of the microcapillary array chip 504.

[0081] In some examples, the microcapillary array do not extend to edge of the microcapillary array chip 504. That is to say, there may be a margin between the edge of themicrocapillary array chip 504 and the edge of the microcapillary array, where the margin does not include any microcapillaries.

[0082] The microcapillary array chip 504 may additionally include a height 706, a width 708, and a length 710. In some examples, the width 708 and the length 710 may be approximately the same distance. In some examples, either or both of the width 708 and the length 710 may be 30.0, 30.5, 31.0, 31.5, 32.0, 32.5, 33.0, 33.5, 34.0, 34.5, 35.0, 35.5, 36.0, 36.5, 37.0, 37.5, 38.0, 38.5, 39.0, 39.5, 40.0, 40.5, 41.0, 41.5, 42.0, 42.5, 43.0, 43.5, 44.0, 44.5, 45.0, 45.5, 46.0, 46.5, 47.0, 47.5, 48.0, 48.5, 49.0, 49.5, 50.0, 50.5, 51.0, 51.5, 52.0, 52.5, 53.0, 53.5, 54.0, 54.5, 55.0, 55.5, 56.0, 56.5, 57.0, 57.5, 58.0, 58.5, 59.0, 59.5, 60.0, 60.5, 61.0, 61.5, 62.0, 62.5, 63.0, 63.5, 64.0, 64.5, 65.0, 65.5, 66.0, 66.5, 67.0, 67.5, 68.0, 68.5, 69.0, 69.5, 70.0, 70.5, 71,0, 71,5, 72,0, 72.5, 73.0, 73,5, 74,0, 74.5, or 75.0 mm or within a range defined by any two of the previous values, though in some instances other values may be suitably implemented. In some examples, either or both of the width 708 and the length 710 may be about 50 mm to about 55 mm. In some examples, either or both of the width 708 and the length 710 may be about 53.5 mm. In some examples, the height 706 may be about 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 mm or within a range defined by any two of the previous values, though in some instances other values may be suitably implemented. In some examples, the height 706 is about 0.9 to 1.1 mm. In some examples, the height 706 is about 1.0 mm.

[0083] A chip holder can receive a microcapillary array chip and properly position it within a microcapillary loader in accordance with the present disclosure. FIGS. 8A-8B illustrates views of a chip holder 502 that can receive the microcapillary array chip 504 discussed with reference to FIGS. 7A-7B. The chip holder 502 can include a depression 802, a shelf edge 804, outer corners 806, notches 808. The shelf edge 804 can be a part of the depression 802. The shelf edge 804 can provide support for a microcapillary array chip 504 placed m the depression 802 while allowing a portion of the bottom surface 616 of the microcapillary array chip 504 to remain open to the air. Spacing between the bottom 616 of the microcapillary array chip 504 and the bottom 822 of the depression 802 when the microcapillary array chip 504 is placed in the chip holder 502 is also shown in FIG. 11 (as spacing 1106). In some alternative examples, the chip holder 502 is open and does not include the bottom 822. The distance between edges of the depression 802 include an outer width 812and an outer length 816. The distance between edges of the shelf edge 804 include an inner width 810 and an inner length 814. In some examples, the inner width 810 and the inner length 814 are approximately equal. In some examples, the outer width 812 and the outer length 816 are approximately equal.

[0084] The inner width 810 and the inner length 814 may be smaller than the respective width and length of the microcapillary array chip 504. That is to say, the inner width 810 may be smaller than the microcapillary array chip width 708 and the inner length 814 may be smaller than the microcapillary array chip length 710, The inner width 810 may be smaller than the width 708 by 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 mm, or within a range defined by any two of the previous values, although in some instances other values may be suitably implemented. The inner length 814 may be smaller than the length 710 by 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 mm, or within a range defined by any two of the previous values, although in some instances other values may be suitably implemented.

[0085] The outer width 812 and outer length 816 may be slightly larger than the respective width and length of the microcapillary array chip 504. That is to say, the outer width 812 may be larger than the width 708 of the microcapillary array chip 504 and the outer length 816 may be larger than the length 710 of the microcapillary array chip 504. The outer width 812 may be larger than the width 708 of the microcapillary array chip 504 by 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 mm, or within a range defined by any two of the previous values, although in some instances other values may be suitably implemented. In some examples, the outer width 812 may be larger than the width 708 of the microcapillary array chip 504 by 0.8 to 1.2 mm. In some examples, the outer width 812 may be larger than the width 708 of the microcapillary array chip 504 by 1.0 mm. The outer length 816 may be larger than the length 710 of the microcapillary array chip 504 by 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 mm, or within a range defined by any two of the previous values, although in some instances other values may be suitably implemented. In some examples, the outer length 816 may be largerthan the length 710 of the microcapillary array chip 504 by 0.8 to 1.2 mm. In some examples, outer length 816 may be larger than the length 710 of the microcapillary array chip 504 by 1.0 mm. It may be desirable that the difference between the outer width 812 and the width 708 of the microcapillary array chip 504 and / or the difference between the outer length 816 and the length 710 of the microcapillary array chip 504 be small enough that the microcapillary array chip 504 be limited from substantial movement when the loader is use. It may be desirable that the difference between the outer width 812 and the width 708 of the microcapillary array chip 504 and / or the difference between the outer length 816 and the length 710 of the microcapillary array chip 504 be large enough that the microcapillary array chip 504 can be readily removed from the chip holder 502. The notches 808 can provide an open area where edges of the microcapillary array chip 504 can be grasped after being placed in the depression 802 of the chip holder 502, for example to remove the microcapillary array chip 504 from the chip holder 502.

[0086] The shelf edge 804 may be inset from a top surface 820 of the chip holder 502 by a shelf depth 818. In some examples, the shelf depth 818 may be about the same as the height 706 of the microcapillary array chip 504. In such examples, when the microcapillary array chip 504 is placed in the chip holder 502, the top surface 702 of the microcapillary array chip 504 is flush, or approximately flush, with the top surface 820 of the chip holder 502.

[0087] The outer corners 806 can be shaped to contact corresponding surfaces of the loader base.

[0088] In some alternative examples, the chip holder can be integrated into the microcapillary loader base. In such examples, the chip holder may not be removable. In such embodiments, the microcapillary array chip can be placed onto the microcapillary loader base at an appropriate position.Microcapillary Loader Base

[0089] FIG. 9A--9B illustrates a loader base 900 of the microcapillary loader 500 discussed with reference to FIGS. 5A--5B. The loader base 900 can include features previously discussed, such as the base portion 508, the reservoir tray 510, the rails 512a and 512b, and the handle 514. The loader base 900 can include a chip holder depression 902, which in turn can include corners 908. The reservoir tray 510 can include a reservoir tray opening 904 andreservoir tray sides 906. The reservoir tray opening 904 and the reservoir tray sides 906 can be sized and / or shaped to receive the reservoir 506. In some examples, the reservoir tray opening 904 is sized to accept the trough portion 606 of the reservoir tray sides 906. In some examples, the top surfaces of the reservoir tray sides 906 are positioned to interact with the lip 604 and the overhang 614 of the reservoir 506 to secure the reservoir 506 within the reservoir tray opening 904. The reservoir tray 510 can also include locking components 910. The locking components 910 can be used to lock and / or secure the reservoir 506 within the reservoir tray 510. In some examples, in a locked state, the locking components 910 can prevent the reservoir 506 from being removed from the reservoir tray 510. In some embodiments, the reservoir 506 is single-use and disposable. Accordingly, in some embodiments, the reservoir 506 is unlocked from the reservoir tray 510 and removed after use while the loader base 900 and reservoir tray 510 may be reused with a new reservoir 506,

[0090] In alternative examples, the loader base 900 can include alternatives to rails 512a and 512b for allowing the reservoir tray 510 to slide relative to a positioned microcapillary array chip 504. In some examples, the reservoir tray 510 can slide over two flat surfaces of the loader base 900. The two flat surfaces can guide the reservoir tray 510 such that the appropriate vertical distance is maintained between the reservoir tray 510 and the microcapillary array chip 504 during fluid loading.

[0091] The corners 908 of the chip holder depression 902 can mate with the outer corners 806 of the chip holder 502. When the chip holder 502 is positioned within the chip holder depression 902, the corners 908 can help to prevent and / or inhibit motion of the chip holder 502 relative to the loader base 900.Loading a Microcapillary Array Chip

[0092] FIG. 10A illustrates a method 1000 of using a microcapillary loader of the present disclosure.

[0093] At step 1002, the microcapillary array chip is positioned in the chip holder. The microcapillary array chip can be positioned within a depression of the chip holder such that the microcapillary array chip is supported. At least a portion of the bottom surface of the microcapillary array chip may not contact the chip holder when the microcapillary array chip is positioned in the chip holder. When positioned in the depression of the chip holder,microcapillaries of the microcapillary array chip may be open and / or unobstructed on both a top surface of the microcapillary array chip and on a bottom surface of the microcapillary array chip.

[0094] At step 1004, the chip holder is positioned in the loader base. Positioning the chip holder may include aligning outer corners of the chip holder with corners of a depression in the loader base. In some alternative examples, the chip holder can be positioned in loader base prior to the microcapillary array chip being positioned m the chip holder (e g., steps 1002 and 1004 can be performed a reverse order relative to the order depicted in FIG.10 A).

[0095] At step 1006, the reservoir is positioned in the reservoir tray, A lip and / or overhang of the reservoir can interact with sides of the reservoir tray when positioned. The reservoir can be secured to the reservoir tray using a locking mechanism. After the reservoir is secure within the reservoir tray, the reservoir tray can be slid over the rails so that the reservoir is in the desired starting position. For example, the starting position of the reservoir may be in a position where the fluid opening in the bottom of the reservoir is positioned against a solid portion of the base or the chip holder that does not contain any microcapillaries so that liquid may be added to the reservoir without any liquid passing through the fluid opening.

[0096] At step 1008, the reservoir is filled with liquid. The liquid can include a sample for analysis. For example, the liquid can include a cell sample. The liquid may additionally or alternatively include reagents.

[0097] At step 1010, the reservoir is slid across the microcapillary array chip. A fluid opening of the reservoir can contact or remain in close proximity to a top of the microcapillary array as the reservoir slides across the microcapillary array chip. When in contact with the top of the microcapillary array, the fluid opening can provide a seal with the microcapillary openings such that the pressure provided by the fluid in the reservoir can push fluid into the capillaries in a controlled manner. The reservoir can be slid by sliding the reservoir tray. In some examples, the reservoir and the reservoir tray can be slid manually (e.g., by a user). In some examples, a user can grasp and pull a handle attached to the reservoir tray to slide the reservoir across the microcapillary array chip.

[0098] At step 1012, the filled microcapillary array chip is placed within an analysis device. The analysis device may be a sample screening and recovery system as discussed with reference to FIGS. 2A-2E.

[0099] FIG. 10B includes a series of top-down images of a method 1050 of a user loading a microcapillary array chip. The reservoir tray starts at a chip loading position. At the loading position, the reservoir tray does not obstruct access of the chip holder to a depression in the loader base that can receive the chip holder.

[0100] At step 1052, a chip holder containing a microcapillary array chip is inserted into a loader base.

[0101] At step 1054, an empty reservoir is inserted into the reservoir tray. The reservoir can be secured to the tray using locking mechanisms.

[0102] At step 1056, the reservoir tray and reservoir is slid to a reagent loading position at a first end of the microcapillary array chip. As shown in FIG, 10B, a user may use a handle coupled to the reservoir tray to move the reservoir.

[0103] At step 1058, liquid is added to the reservoir. As discussed herein, the liquid can include samples and / or reagents. A liquid volume of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 mL of liquid, or within a range defined by any two of the previous values, can be added to the reservoir. In some examples, the 1-3 mL of liquid is added to the reservoir. Liquid can be added via pipette or any other suitable implement.

[0104] At step 1060, the reservoir is slid across the chip to load the reservoir with liquid. The handle coupled to the reservoir tray can be rotated to be oriented toward the loading position and pulled to slide the reservoir as shown. Sliding the reservoir across the microcapillary array chip can cause fluid from the reservoir to transfer to microcapillaries of the microcapillary array chip. After transfer of fluid, the reservoir tray can be returned to the loading position to allow the chip to be retrieved from the chip holder.

[0105] FIG. 11 is a cross-sectional side view of the loader 500 with a reservoir 506, microcapillary array chip 504, and chip holder 502 positioned for liquid loading of microcapillaries. Dotted arrow A indicates movement of fluid from the reservoir 506 through the fluid opening 608 to the microcapillary array chip 504 to allow for loading of themicrocapillaries. When the microcapillary array chip 504 and chip holder 502 are positioned in the microcapillary loader 500, the bottom of the microcapillary array chip 504 is spaced from the bottom 822 of the depression 802 by a spacing 1106, allowing the bottom of the microcapillary array chip 504 to be at least partially open.

[0106] Dashed line B indicates motion of the reservoir tray 510 and reservoir 506 across the microcapillary array chip 504 when loading the array of microcapillaries with fluid. The reservoir tray 510 and the reservoir 506 can begin at a first end 1102 of the microcapillary array chip 504, A user can then slide the reservoir tray 510 and the reservoir 506 from the first end 1102 to the second end 1104 of the microcapillary array chip 504 to allow all the microcapillaries of the microcapillary array chip 504 to be loaded with liquid.

[0107] While specific examples have been provided, the above description is illustrative and not restrictive. Any one or more of the features of the previously described embodiments can be combined in any manner with one or more features of any other embodiments in the present invention. Furthermore, many variations will become apparent to those skilled in the art upon review of the specification. Many modifications and variations of this application can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments and examples described herein are offered by way of example only, and the application is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which the claims are entitled.

[0108] The examples set forth above are provided to give those of ordinary skill in the art a complete disclosure and description of how to make and use the embodiments of the compositions, systems and methods of the invention, and are not intended to limit the scope of what the inventors regard as their invention. Modifications of the above-described modes for carrying out the invention that are obvious to persons of skill in the art are intended to be within the scope of the following claims. All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains.

[0109] All headings and section designations are used for clarity and reference purposes only and are not to be considered limiting in any way. For example, those of skill in the art will appreciate the usefulness of combining various aspects from different headings and sections as appropriate according to the spirit and scope of the invention described herein.

[0110] All references cited herein, including all patents, patent publications, and other published references, are hereby incorporated by reference herein in their entireties and for all purposes to the same extent as if each individual publication or patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety for all purposes.Divided Reservoir and Partial Loading of a Microcapillary Chip

[0111] Reservoirs can be divided into sections. For example, a reservoir may include two or more trough portions. Multiple trough portions may allow for a single reservoir to load two or more different liquids to a microcapillary chip. In some examples, multiple trough portions can allow for loading of multiple different samples or sample types to a single microcapillary chip.

[0112] Additionally or alternatively, a loader as discussed herein may be used to partially fill a microcapillary array. For instance, a reservoir of the loader can be slid across only a portion of the length of a microcapillary chip to load a portion, but not all, of the microcapillaries of the microcapillary array. Partial filling of the microcapillary array may be desirable w’hen not all microcapillaries of a microcapillary array chip are needed to conduct a screening assay,

[0113] FIGS. 12A-12C show top-down schematic views of a divided reservoir partially loading a microcapillary chip. FIG. 12A show's initial placement of the reservoir 1204 near a first end 1212 of a microcapillary array chip 1202. The reservoir 1204 can include more than one trough portion. For example, in the example depicted in FIGS. 12A-12C, the reservoir 1204 can include a four trough portions: a first trough portion 1206a, a second trough portion 1206b, a third trough portion 1206c, and a third trough portion 1206d. It is to be understood that other numbers of trough portions may be suitably implemented. In some examples, the reservoir 1204 can include 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 trough portions. The trough portions 1206a, 1206b, 1206c, 1206d may be separated by interior walls of the reservoir 1204. The trough portions 1206a, 1206b, 1206c, 1206d can each be loaded with a liquid for loading to the microcapillary array chip 1202. The reservoir 1204 can be translated from the first end 1212 of the microcapillary array chip 1202toward the second end 1214 of the microcapillary array chip 1202. Each of the trough portions 1206a, 1206b, 1206c, 1206d may have a corresponding fluid opening.

[0114] FIG. 12B shows the microcapillary array chip 1202 and the reservoir 1204 of FIG.12A after the reservoir 1204 has been slid over a portion of the microcapillary array chip 1202 to a final position 1216. The final position 1216 can be an intermediate position somewhere between the first end 1212 and the second end 1214. The trough portions 1206a, 1206b, 1206c, 1206d can load their respective liquids into microcapillary array regions 1208a, 1208b, 1208c, 1208d respectively. As the trough portions 1206a, 1206b, 1206c, 1206d can include different liquids, the microcapillary array regions 1208a, 1208b, 1208c, 1208d can each include different liquids. In some examples, each array region microcapillary array regions 1208a, 1208b, 1208c, 1208d may include a different sample or a different sample type. The width of each of the microcapillary array regions 1208a, 1208b, 1208c, 1208d may be affected by the corresponding width of the fluid opening of the trough portion 1206a, 1206b, 1206c, 1206d from which liquid of the microcapillary array regions 1208a, 1208b, 1208c, 1208d were loaded.

[0115] FIG. 12C shows the microcapillary array chip 1202 after removal of the reservoir 1204. Each of the microcapillary array regions 1208a, 1208b, 1208c, 1208d may include a length 1210. The length 1210 can depend on the final position 1216. That is to say, the length 1210 can be longer if the final position 1216 is closer to the second end 1214. The longer the length 1210, the smaller an unloaded region 1218 will be. The unloaded region 1218 can include microcapillaries that do not contain fluid loaded from the reservoir 1204.Reverse Chip Loading

[0116] Addition of a hydration gel to one side of a microcapillary chip can prevent or inhibit evaporation of microcapillary well contents. The hydration gel can block evaporation of fluid on the side of the microcapillary chip on which it is placed. Advantageously, the hydration gel can allow for multi-step reagent and cell introduction workflows and / or extended incubation steps using a microcapillary’ chip as discussed herein.

[0117] FIG. 13A depicts a method 1300 of reverse microcapillary chip loading including addition of a hydration gel to a microcapillary chip. Reference is also made to FIG.13B, which includes a series of schematic drawings accompanying the steps shown in FIG.13 A.

[0118] At step 1302, cells and / or assay reagents are loaded into microcapillary wells 1354 of the microcapillary chip 1352. The cells and / or assay reagents can be distributed onto a top surface of the microcapillary chip 1352. The cells and / or assay reagents can be added in accordance with the present disclosure, for example with reference to discussion of FIGS.3A-12C.

[0119] At step 1304, the hydration gel 1356 can be applied to the microcapillary chip 1352. The hydration gel 1356 can be placed over the chip to maintain moisture within the microcapillary wells 1354 during one or more subsequent incubation steps. The hydration gel 1356 can be a hydrogel. The hydration gel 1356 can be an agarose. The agarose can be a 0.5%, 0.6 %, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1,2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, or 2.5% agarose gel, or within a range defined by any of the preceding two values, though in some instances values outside these ranges may be suitably implemented. In some examples, the agarose is a 1% agarose. In some examples, the agarose is a 2% agarose.

[0120] At step 1306, incubate the covered microcapillary chip 1352. Incubation conditions can be particular to the assay type and / or cell type. During incubation, the microcapillary chip 1352 can include a closed side 1358. The closed side 1358 can be sealed by the hydration gel 1356. In some examples, the ends of the microcapillary wells 1354 are sealed by the hydration gel 1356. In other examples, there can be fluid communication between the ends of the microcapillary wells 1354 on the closed side 1358. On the opposite side of the microcapillary chip 1352 is an open side 1360. On the open side 1360, the microcapillary wells 1354 can be open to ambient air.

[0121] At step 1308, the microcapillary chip 1352 is inverted. After inversion, the closed side 1358 can face downward and the open side 1360 can face upward.

[0122] At step 1310, additional reagents and / or wash buffer can be added to the microcapillary wells 1354. Without removing the hydration gel 1356 such that it remains on now downward- facing closed side 1358, the additional reagents and / or wash buffer can be added to the upward-facing open side 1360. In some examples, additional cells may be added during step 1310. The additional reagents, wash buffer, and / or additional cells can be added inaccordance with the present disclosure, for example with reference to discussion of FIGS. 3A-12C.

[0123] It is to be understood that, after step 1310, the microcapillary chip 1352 can be inverted and / or re-inverted as needed for additional incubation step(s) 1306 and additional reagent and / or wash buffer addition step(s) 1310. Such steps can be repeated once, twice, or more with repeated addition of the same reagents and / or wash buffer or different, new reagents.

[0124] At step 1312, the microcapillary chip 1352 can be screened in accordance with the present disclosure, for example with reference to discussion of FIGS. 1 A-4. Screening may include imaging and / or sample extraction from the microcapillary chip 1352, In some examples, the hydration gel 1356 can remain on the microcapillary chip 1352 during screening. In such examples, the microcapillary chip 1352 can be oriented such that the open side 1360 is oriented downward and the wells 1354 are imaged from below the chip 1352 through the open side. In some such examples, downward orientation of the open side 1360 also allows for the sample in a microcapillary well 1354 to be collected once it is ejected from the microcapillary chip 1352 in the downward direction. In some examples, presence of the hydration gel 1356 on the microcapillary chip 1352 does not prevent imaging of the contents of the microcapillary wells 1354. In other embodiments, the hydration gel 1356 can be removed from the microcapillary chip 1352 prior to the screening step 1312.

[0125] Although the embodiments depicted in FIGS. I3A and 13B utilize a hydration gel 1356 on one side 1358, it will be appreciated that the sequential reverse chip loading procedure may be used without the hydration gel. For example, the incubation time at step 1306 may be short enough that evaporation of the nucrocapillary contents is not a concern.

[0126] Advantageously, reverse chip loading allows for a variety of potential assay types. For example, reverse chip loading allows for timed cell introduction for functional assays. Cells can be sequentially added. For instance, in an example assay, reporter cells and / or T cells can be added into the chip after antibody secretion is complete within capillaries. Such sequential addition enables precise evaluation of functional immune responses without disrupting the initial antibody production phase.

[0127] Reverse chip loading allows for sequential and / or layered reagent delivery. Such sequential and / or layered reagent delivery can enable certain multiplex assays. Sequential and / or layered reagent delivery can avoid disruption of the initial assay setup. Reagents forsequential addition can include detection antibodies, substrates, or buffers, or the like. Such an approach may be particularly suited for multiplexed biomarker or pathogen detection.

[0128] Reverse chip loading can be implemented for competitive binding assays. Antibodies, for example floating antibodies or bead-bound competitive antibodies, can be introduced via reverse loading to target the same binding sites. Reverse loading of antibodies can allow for real-time analysis of antibody kinetics and competitive interactions. The microcapillary chip can be subjected to screening shortly after introduction of the antibodies, as there is no need to wait for incubation for protein secretion.

[0129] Reverse chip loading can be implemented to allow for targeted washing. Targeted washing may be desirable to enhance the signal-to-noise ratio within the microcapillaries. Wash buffers can be added (or sequentially added) through reverse loading. The wash buffers can assist in removing unbound assay reagents while preserving the integrity of the bound compl exes.EXAMPLESUse of Microcapillary Loader

[0130] FIGS. 14A-14C show images of example microcapillary array chips loaded using a loader in accordance with the present disclosure. In the examples depicted in FIGS.14A-14C, the microcapillary array chip includes 1.5 million microcapillaries. FIGS. 14A is a field-of view image showing the distribution of beads on a microcapillary array chip.

[0131] FIG. 14B depicts a field-of-view with a uniform distribution of cells on a microcapillary array chip.

[0132] FIG. 14C is a fluorescence image showing antibody-secreting cells from the same microcapillary array chip of FIG. 14B after loading. The cells appear to have an even distribution across the microcapillary array and the antibody secretion assay appears to have proceeded as expected.Reverse Chip Loading

[0133] A microcapillary chip was loaded in accordance with the method discussed with reference to FIG. 13 A. E. coli cells were first loaded into microcapillary wells of a microcapillary chip. A hydration gel (e.g., LB agar) was placed on a top face of the microcapillary chip. The E. coli cells were incubated for 4-5 hours under optimal conditions. After incubation, the microcapillary chip was inverted, such that the open side faced upwardand the hydration gel side faced downward. Without removing the hydration gel, additional reagents (for example, horseradish peroxidase (HRP) reagent, target peptide, and lysis buffer) were added to the open side. The microcapillary chip was subjected to a second incubation (e.g., 15 to 20 minutes at 37 °C, though incubation times of 5, 10, 25, 30, 35, 40, 45, 50, 55, or 60 could be suitably be implemented). The second incubation allowed reagent interaction and cell lysis.

[0134] FIG. 15 is an image of taken during fluorescent screening of the microcapillary chip. Individual microcapillary wells of the microcapillary chip were screened for E. coli exhibiting high fluorescence signals indicative of HRP activity. The image was taken in the Cy5 channel, with 200 ms exposure, and a gain of 2. The reagents included a mixture of 100 mM phosphate buffer, 2x Amplex UltraRed (2x), HRP (0.4 U / ml), CML Peptide 1.6 mM, and 2X FastBreak Lysis added.

Claims

WHAT IS CLAIMED IS:

1. A system for loading a microcapillary array with a liquid, the system comprising:a base configured to receive a microcapillary array chip; anda reservoir configured to receive a liquid and translatably coupled to the base, the reservoir comprising a first fluid opening,wherein, when the microcapillary array chip is positioned in the base, the reservoir and first fluid opening are configured to translate relative to the base and the microcapillary array chip parallel to a top surface of the microcapillary array chip.

2. The system of claim 1, the base comprising one or more rail, the reservoir coupled to the one or more rail, wherein the one or more rail is configured to allow the reservoir to slide relative along a horizontal plane of the base.

3. The system of claim 2, wherein the base comprises two rails, the two rails configured to allow the reservoir to slide along the horizontal plane of the base.

4. The system of claim 3, wherein a first of the two rails is positioned on a first side of the base, and wherein a second of the two rails is positioned on a second side of the base, the second side of the base opposing the first side of the base.

5. The system of any one of claims 1 to 4, wherein the base comprises a depression, the depression configured to receive the microcapillary array chip.

6. The system of any one of claims 1 to 5, comprising a reservoir tray translatably coupled to the base, the reservoir tray configured to receive the reservoir.

7. The system of claim 6, wherein the reservoir tray is configured for manual sliding.

8. The system of claim 7, wherein the reservoir tray comprises a handle.

9. The system of claim 8, wherein the handle is rotatable to allow a user to pull the reservoir tray in two opposite directions.

10. The system of any one of claims 6 to 9, comprising a motor configured to move the reservoir tray relative to the base.

11. The system of any one of claims 6 to 10, wherein the reservoir is detachable from the reservoir tray.

12. The system of any one of claims 6 to 11, wherein the reservoir tray comprises at least one lock configured to secure the reservoir within the reservoir tray.

13. The system of any one of claims 6 to 12, the reservoir tray comprising a rectangular frame configured to receive the reservoir.

14. The system of any one of claims 6 to 13, the reservoir tray comprising two sides configured to receive the reservoir.

15. The system of any one of claims 6 to 14, the reservoir tray comprising a first side aperture configured to slidingly receive a first rail of the base and a second side aperture configured to slidingly receive and a second rail of the base.

16. The system of any one of claims 1 to 15, comprising a chip holder to hold the microcapillary array chip, wherein the base is configured to receive the chip holder.

17. The system of claim 16, the base comprising a depression, the depression configured to receive the chip holder.

18. The system of claim 17, wherein sides of the depression mate with sides of the chip holder, and wherein the sides of the depression are configured to prevent lateral movement of the chip holder relative to the base.

19. The system of any one of claims 16 to 18, wherein the chip holder is configured to be placed in an analysis device.

20. The system of any one of claims 16 to 19, the base comprising an opening wherein, when the microcapillary array chip is positioned in the chip holder and the chip holderis positioned on the base, at least a portion of the microcapillary array chip is positioned above the opening.

21. The system of any one of claims 1 to 20, wherein the reservoir is configured to contact a top surface of the microcapillary array chip when the microcapillary array chip is positioned for liquid loading.

22. The system of any one of claims 1 to 21, wherein the reservoir is configured to receive 1~3 mb of liquid,23. The system of any one of claims 1 to 22, the first fluid opening running at least a majority of a length of the reservoir.

24. The system of any one of claims 1 to 23, the first fluid opening extending longitudinal to the reservoir.

25. The system of claims 1 to 24, the first fluid opening comprising a width of about 0.5 to about 1.0 mm.

26. The system of claim 25, wherein the width of the first fluid opening is about 0.8 to about 0.9 mm.

27. The system of any one of claims 1 to 26, the first fluid opening comprising a length about of 35 to about 50 mm.

28. The system of claim 27, wherein the length of the first fluid opening is about 40 to about 45 mm.

29. The system of any one of claims 1 to 28, the reservoir comprising a height about 10 mm or more.

30. The system of any one of claims 1 to 29, wherein the reservoir comprises a first end and a second end opposite the first end, a first side and a second side opposite the first side, wherein the first end comprises a second fluid opening and the second end comprises thefirst fluid opening, wherein the first side and second side taper from the first end to the second end.

31. The system of any one of claims 1 to 30, wherein the reservoir is symmetrical about the first fluid opening.

32. The system of any one of claims 1 to 31, wherein the reservoir comprises two or more trough portions, wherein each trough portion is configured to separately receive liquid, and wherein each trough portion comprises a separate fluid opening.

33. The system of any one of claims 1 to 32, the system comprising the microcapillary array chip,34. The system of claim 33, wherein the reservoir is dimensioned such that the hydrostatic pressure exerted on the microcapillaries of the microcapillary array chip from loaded liquid via the first fluid opening does not exceed a capillary force m the microcapillaries.

35. The system of any one of claims 1 to 34, wherein the liquid comprises a cell sample.

36. The system of any one of claims 1 to 35, wherein the liquid comprises a reagent.

37. A method of loading a microcapillary array chip, the method comprising: introducing liquid to a reservoir; andsliding the reservoir across a first surface of the microcapillary array chip from a first position over the microcapillary array chip to a second position over the microcapillary array chip, wherein the sliding of the reservoir allows the liquid to transfer from the reservoir to microcapillaries of the microcapillary array chip.

38. The method of claim 37, comprising positioning a reservoir in a reservoir tray.

39. The method of claim 38, comprising positioning a microcapillary array chip in a base, wherein the base is translatably coupled to the reservoir tray.

40. The method of claim 39, wherein positioning the microcapillary array chip comprises positioning the microcapillary array chip in a chip holder and positioning the chip holder in the base, wherein the chip holder is configured to hold the microcapillary array chip and mate with the base.

41. The method of any one of claims 37 to 40, comprising adding about 1 to about 3 mL of liquid to the reservoir.

42. The method of any one of claims 37 to 41, wherein the liquid comprises a cell sample,43. The method of any one of claims 37 to 42, comprising placing, after transferring liquid to the microcapillaries of the microcapillary array chip, the microcapillary array chip in an analysis device.

44. The method of any one of claims 37 to 43, comprising positioning the reservoir at a first position, wherein, at the first position, the reservoir contacts the microcapillary array chip at the first end.

45. The method of any one of claims 37 to 44, wherein the sliding is conducted by applying a force to a handle, the handle coupled the reservoir.

46. The method of any one of claims 37 to 45, wherein the sliding comprises translating the reservoir along one or more rails.

47. The method of any one of claims 37 to 46, further comprising applying a hydration gel to the first surface.

48. A method of loading a microcapillary array chip, the method comprising:loading a first fluid into a plurality of microcapillaries of a microcapillary chip via openings in a first surface of the microcapillary chip; andloading a second fluid into the plurality of microcapillaries via openings in a second surface of the microcapillary chip, the second surface opposite the first surface.

49. The method of claim 48, further comprising screening the microcapillary chip.

50. The method of claim 49, further comprising applying a hydration gel to a first surface of the microcapillary chip after loading the first fluid into the plurality of microcapillaries.

51. The method of claim 50, wherein the hydration gel comprises a hydrogel.

52. The method of claim 51, wherein the hydration gel comprises an agarose.

53. The method of claim 52, wherein the agarose is a 1% agarose or 2% agarose.

54. The method of claim 50 or 53, wherein, during the step of screening, the hydration gel remains applied to the microcapillary chip.

55. The method of any one of claims 49 to 54, the screening further comprising:imaging the microcapillary chip to determine at least one microcapillary of interest; andisolating contents of the at least one microcapillary of interest.

56. The method of any one of claims 48 to 55, further comprising incubating, after the loading the first fluid and before loading the second fluid, the microcapillary chip.

57. The method of any one of claims 48 to 56, wherein the first fluid comprises first cells.

58. The method of claim 57, wherein the first cells comprise prokaryotic cells59. The method of claim 58, wherein the first cells comprise bacteria cells.

60. The method of claim 59, wherein the first cells comprise E. coli cells.

61. The method of claim 57, wherein the first cells comprise eukaryotic cells.

62. The method of claim 61, wherein the first cells comprise B cells.

63. The method of any one of claims 48 to 62, wherein the second fluid comprises any one or more of assay reagents, wash buffer, or second cells.

64. The method of claim 63, wherein the second cells comprise reporter cells.

65. The method of claim 63 or 64, wherein the second cells comprise T cells.

66. The method of any one of claims 48 to 65, wherein the loading the first fluid or the loading the second fluid comprises the steps of any one of claims 37 to 46.

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