Devices, holders, kits and methods for sample processing

Abstract

Described herein is a holder for holding a fluid droplet forming device therein for centrifugation. The holder comprises a holding tray having a plurality of slots for hosting fluid droplet forming devices. Further described is a kit comprising the holder and a fluid droplet forming device that fits in the holder. Further described is a method of forming a fluid droplet on a substrate with the kit.

Description

[0001] DEVICES, HOLDERS, KITS AND METHODS FOR SAMPLE PROCESSING

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] The present application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63 / 638,664, filed April 25, 2024, which is incorporated herein by reference in its entirety.

[0004] BACKGROUND

[0005] In a variety of scientific applications, it is desirable to create linked processes for biochemical reactions and / or other processing, and then to produce a designed and / or spatially patterned array of those fluids into “spots” (i.e., biological fluids, chemical fluids, and the like) onto a variety of substrates. Doing so allows for high throughput assaying of these fluid samples in, for example, screening (e.g., diagnostic / prognostic tests), biological analyses, biochemical analyses, and / or chemical analyses in a highly parallel fashion. Additionally, the ability to affix multiple samples on a single substrate, such as a variety of glass microscope slides, greatly reduces the cost of performing experiments e.g., through reduction of the volume of reagents required for multiple single runs), provides significant time savings, and also can reduce technical replicate issues (e.g., batch effects) by performing the same assay on the same substrate in parallel.

[0006] Existing devices and techniques that can produce multiple spots have disadvantages associated therewith, and are often incompatible with emerging techniques such as fluidics, robotics, and / or automation workflows. For example, existing device and techniques may require significant manual labor to produce an array, and / or may suffer from bleeding (not water-tight seal), producing an array of spots with an inconsistency in fluid distribution. Some techniques leave a residue on the slide (substrate) around where the fluid spots are produced, thereby impeding reagent flow and the utility of these assays for newer technologies that utilize fluidics, robotics, and / or other automation workflows to conduct standard and custom analyses. There is thus a need for novel devices, kits, and methods for providing the patterned and / or small volume sample arrays that are compatible with the newer high-throughput analysis automation technology. The present invention addresses this need.

[0007] SUMMARY

[0008] In some aspects, the present invention is directed to the following non-limiting embodiments:

[0009] Holder

[0010] In some aspects, the present invention is directed to a holder.

[0011] In some embodiments, the hold comprises a holding tray having a plurality of slots for hosting one or more fluid droplet forming devices.

[0012] In some embodiments, the holder holds one or more fluid droplet forming devices during centrifugation.

[0013] In some embodiments, during the centrifugation, a downward centrifugal force is applied to the fluid droplet forming devices such that samples loaded in the fluid droplet forming devices move downwardly along the devices to form fluid droplets.

[0014] In some embodiments, the plurality of slots are for hosting fluid droplet forming devices having a substantially rectangular cuboid shape, a substantially cylindrical shape, or a substantially oval cylindrical shape.

[0015] In some embodiments, the holder fits a centrifuge plate holder configured to hold microplates for centrifugation.

[0016] In some embodiments exterior dimensions of the holder, or portions thereof, are substantially the same as those of a microplate, such that the holder fits a centrifuge plate holder.

[0017] In some embodiments, bottom dimensions of the holder are substantially the same as those of a microplate.

[0018] In some embodiments bottom outside flange dimensions of the holder are substantially the same as those of a microplate.

[0019] In some embodiments, lateral wall dimensions of the holder are substantially the same as those of a microplate.

[0020] In some embodiments, height dimensions of the holder are substantially the same as those of a microplate. In some embodiments, the holding tray comprises at least two holding trays.

[0021] In some embodiments, each of the holding trays comprises: a holder base under the holding tray; and a holder lid above the holding tray.

[0022] In some embodiments, an upper surface of the holder lid is configured to engage a lower surface of the holder base.

[0023] In some embodiments, when the holding trays are stacked, adjacent holder bases and holder lids maintain a positioning of adjacent holding trays relative to each other, providing for stable vertical stacking.

[0024] In some embodiments, the holding tray comprises an aligner having the plurality of slots, and a side tray.

[0025] In some embodiments, one or more slots of the plurality of slots has an alignment cutout, such that a fluid droplet forming device having a complementary alignment tab can properly align with the slot when placed therein.

[0026] Kit

[0027] In some aspects, the present invention is directed to a kit,

[0028] In some embodiments, the kit comprises a fluid droplet forming device for forming an array of fluid droplet thereon.

[0029] In some embodiments, the fluid droplet forming device comprises a substrate; and a droplet forming layer on the substrate, which has an upper opening and a lower opening in fluid communication with each other via a passage.

[0030] In some embodiments, the kit further comprises a holder for holding the device during centrifugation.

[0031] In some embodiments, each slot of the plurality of slots holds one fluid droplet forming device.

[0032] In some embodiments, the lower opening is in direct contact with the substrate.

[0033] In some embodiments, a fluid sample introduced into the upper opening of the droplet forming layer moves downwardly via the passage and settles on an upper surface of the substrate via the lower opening in response to a centrifugal force, and forms a fluid droplet on the substrate. In some embodiments, the droplet forming layer is a first patterned template layer having a plurality of apertures for providing the upper opening, the lower opening, and the passage.

[0034] In some embodiments, the droplet forming layer is one or more sample restraining modules for providing the upper opening, the lower opening, and the passage.

[0035] In some embodiments, the fluid droplet forming device comprises a holder alignment tab.

[0036] In some embodiments, the one or more slots of the holding tray has an alignment cutout.

[0037] In some embodiments, the holder alignment cutout and the holder alignment tab align the fluid droplet forming device with the slot.

[0038] In some embodiments, the holder alignment tab is a part of the substrate, or a part of the droplet forming layer.

[0039] In some embodiments, the fluid droplet forming device further comprises a first patterned template layer, and the first patterned template layer comprises the holder alignment tab,

[0040] In some embodiments, the fluid droplet forming device further comprises a first patterned template layer and a second patterned template layer, and the second patterned template layer comprises the holder alignment tab.

[0041] In some embodiments, the fluid droplet forming device further comprise a lid, and the lid comprises the holder alignment tab.

[0042] In some embodiments, the holder comprises a holding tray having a plurality of slots for hosting one or more fluid droplet forming devices,

[0043] In some embodiments, the holder holds one or more fluid droplet forming devices and remains stably in a centrifuge during an application of the centrifugal force by the centrifuge.

[0044] In some embodiments, the holder fits a centrifuge plate holder for holding microplates for centrifugation.

[0045] In some embodiments, exterior dimensions of the holder, or portions thereof, are substantially the same as those of a microplate, such that the holder fits a centrifuge plate holder.

[0046] In some embodiments, bottom dimensions of the holder are substantially the same as those of a microplate.

[0047] In some embodiments, bottom outside flange dimensions of the holder are substantially the same as those of a microplate.

[0048] In some embodiments, lateral wall dimensions of the holder are substantially the same as those of a microplate. In some embodiments, height dimensions of the holder are substantially the same as those of a microplate.

[0049] In some embodiments, the kit further comprises a holder base under the holding tray, or a holder lid above the holing tray.

[0050] In some embodiments, the kit comprises the holder base and the holder lid, and a shape of an upper surface of the holder lid matches a shape of a lower surface of the holder base such that adjacent holder bases and holder lids lock into each other to allow multiple holders for stable vertical stacking.

[0051] In some embodiments, the holding tray comprises an aligner having the plurality of slots, and a side tray.

[0052] Method

[0053] In some aspects, the present invention is directed to a method of forming a fluid droplet with the holder herein.

[0054] In some embodiments, the method comprises introducing a fluid sample into an upper opening of a droplet forming layer of the fluid droplet forming device.

[0055] In some embodiments, the method further comprises placing the fluid droplet forming device in a slot of the holder.

[0056] In some embodiments, the method further placing the holder in a centrifuge plate carrier of a centrifuge.

[0057] In some embodiments, the method further operating the centrifuge to apply a centrifugal force to the holder and the fluid droplet forming device held thereon.

[0058] In some embodiments, the fluid sample moves downwardly via a passage in the droplet forming layer and settles on an upper surface of a substrate via a lower opening in response to the centrifugal force, thereby forming the fluid droplet on the substrate.

[0059] In some embodiments, the method further comprises removing the droplet forming layer from the substrate to make the fluid droplet formed on the substrate accessible for subsequent procedures.

[0060] In some embodiments, the method further comprises forming a patterned array of fluid droplets on the substrate. In some embodiments, the fluid droplet forming device includes a plurality of passages, each of the plurality of passages forming a separate fluid droplet on the substrate, the separate fluid droplets forming the patterned array.

[0061] In some embodiments, the method further comprises placing at least one additional fluid droplet forming device in another slot of the holder.

[0062] In some embodiments, the operating of the centrifuge forms fluid droplets uniformly across the fluid droplet forming devices.

[0063] In some embodiments, the method further comprises placing at least one additional holder in the centrifuge plate carrier of the centrifuge, each of the holder and the at least one additional holder containing one or more of the fluid droplet forming devices.

[0064] BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The following detailed description of exemplary embodiments will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating, nonlimiting embodiments are shown in the drawings. It should be understood, however, that the instant specification is not limited to the precise arrangements and instrumentalities of the embodiments shown in the drawings.

[0066] Figs. 1A-1B illustrate some elements of the device herein, in accordance with some embodiments.

[0067] Figs. 2A-2B, 3A-3B, 4A-4B, 5A-5B, and 6-9 illustrate the first patterned template layer of the device herein, in accordance with some embodiments.

[0068] Figs. 10A-10B and 11 illustrate the second patterned template layer of the device herein, in accordance with some embodiments.

[0069] Fig. 12 illustrates the second patterned template layer of the device herein, in accordance with some embodiments.

[0070] Figs. 13 and 14A-14B are cross-sectional illustrations of the first patterned template layer having funnel-shaped apertures, in accordance with some embodiments.

[0071] Fig. 15 shows two examples of the first patterned template layers, which were printed with poly-lactic acid, in accordance with some embodiments. The thicknesses of the two first patterned template layers are both 3 mm. The nominal diameters of the apertures on the two examples are 3mm and 6mm, respectively. The alignment marks are nominally 3.75 mm thick. Fig. 16 shows two examples of the second patterned template layers, which were printed using poly-lactic acid, in accordance with some embodiments. The thicknesses of the two second patterned template layers are both 3 mm.

[0072] Figs. 17A-17C show certain aspects of an example of a sample process using an exemplary device in accordance with some embodiments disclosed herein. Fig. 17A: the first patterned template layer of the device, holding fluid droplets by surface tension. Fig. 17B: the substrate of the device, after the fluid droplets were transferred thereon. Fig. 17C: the substrate of the device, after the fluid droplets thereon have been dried.

[0073] Figs. 18A-18F show certain aspects of an example of a sample process using an exemplary device in accordance with some embodiments disclosed herein. Fig. 18A: the exemplary device before assembly, which includes a substrate, a wick, a first patterned template layer having 10 apertures, a filter, a second patterned template layer having a window region which allows the apertures in the first patterned template layer to be accessed, and a lid. Fig. 18B: the exemplary device, after assembly (without the lid). Fig. 18C: fluid droplets loaded on the filter of the device. Fig. 18D: the exemplary device, with fluid droplets loaded and completed with the lid. Fig. 18E: the exemplary device, secured with a clip. Fig. 18F: the exemplary device, loaded with fluid droplets, completed, and placed in a centrifuge.

[0074] Fig. 19 illustrates a non-limiting example of a lid, in accordance with some embodiments.

[0075] Figs. 20A-20B illustrate several non-limiting examples of a sample restraining module, in accordance with some embodiments.

[0076] Fig. 21 illustrates some elements of a non-limiting example of the device herein, in accordance with some embodiments.

[0077] Figs. 22A-22B illustrate several non-limiting examples of a first / second patterned template layer, in accordance with some embodiments.

[0078] Fig. 23 illustrates certain aspects of a method of forming a fluid droplet pattern using the device herein, in accordance with some embodiments.

[0079] Fig. 24 illustrates certain aspects of a holder, in accordance with some embodiments.

[0080] Fig. 25 illustrates certain aspects of an aligner of a holding tray, in accordance with some embodiments.

[0081] Fig. 26 illustrates certain aspects of a holder lid, in accordance with some embodiments. Figs. 27A-27K show certain aspects of an example of a sample process using an exemplary kit, in accordance with some embodiments. Fig. 27A: an exemplary fluid droplet forming device before assembly, which includes a substrate, eight (8) sample restraining modules (which forms a droplet forming layer) on the substrate, and a lid. Fig. 27B: fluid samples loaded into the upper opening of the sample restraining modules. Fig. 27C: the lid is place on the droplet forming layer. Figs. 27D-27E: the assembled fluid droplet forming device, completed with a clip. Figs. 27F-27G: the fluid droplet forming devices are placed in holders. Fig. 27H: the holders containing the fluid droplet forming devices are placed on a plate holder of a centrifuge. Fig. 271: one of the fluid droplet arrays formed on the substrate, after drying. Fig. 27J: the fluid droplet arrays, after staining. Fig. 27K: one of the stained fluid droplets under the microscope.

[0082] Figs. 28A-28B show some aspects of a method of forming a fluid droplet pattern using the kit herein, in accordance with some embodiments.

[0083] DETAILED DESCRIPTION

[0084] The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and / or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed.

[0085] In a variety of scientific applications, it is desirable to consider ways to standardize analyses, reduce batch effects, and scale analytical output. One way to achieve this would be to produce a designed and / or spatially patterned array of fluids into stereotypical “spots” (i.e., biological fluids, chemical fluids, and the like) onto a variety of substrates. Doing this successfully would allow for high throughput assaying of these fluids for the purposes of screening (i.e., diagnostic / prognostic tests) as well as performing biological, biochemical, and chemical analyses in a highly parallel fashion. The ability to affix multiple samples on a single substrate, for example, using a variety of glass microscope slides as the substrate, could greatly reduce the cost of performing experiments (e.g., through reduction of the volume of reagents required for carrying out multiple single runs) as well as provides significant time savings. Another benefit of simultaneously analyzing samples would be the reduction of technical replicate issues (i.e., batch effects) by performing the same assay on the same substrate in parallel.

[0086] Existing devices for preparing arrays of small volume fluid samples have certain shortcomings. For example, some existing devices require a significant amount of manual labor to produce the array. Some have sample bleeding issues. Some produce arrays of spots with an inconsistent fluid distribution. Some leave residue on the slide / substrate around areas where the fluid spots are produced, which impedes reagent flow. Some devices include slides patterned with hydrophobic and hydrophilic regions, which affect the flow of fluids. These shortcomings limit the utility of these devices in newer technologies, such as those utilizing fluidics, robotics, or other automation workflows.

[0087] To address these challenges, the present disclosure describes an adaptable device, as well as a method using the same, which can be customized to arrange fluid spots / droplets in arrays of any pattern, on any sized substrate. The device and method herein allow the accommodation of layering such that processing steps (e g., micro-, ultra-, nanofiltration; heated or cooled wells, etc.) can be added or subtracted, as needed.

[0088] The device herein (a) allows good adherence between the fluid sample and the substrate on which the array is formed, (b) allows for high throughput assays that can be customized in size, number, and dimension (e g, fiducial framing), (c) provides improved consistency in fluid distribution within a spot and between spots (patterning), (d) leaves the substrate free from debris or other contaminants, (e) offers flexibility for use in a wide variety of instrumentation systems, (f) allows for increased flexibility for the materials to be used (e g., allows materials under test or observation to remain in suspension as opposed to directly being deposited from vessel to substrate without observation or other processing), and (g) provides a flexible framework for assembling layers of materials to customize and stage assays in order to allow for “lab-in- suspension” approach before depositing processed fluids to be deposited on a substrate. The device and method herein allow the formation of arrays of fluid droplets / spots using common laboratory systems such as pipettes and centrifuges, and is compatible with automation such as robotics, liquid or bioprinting, or other lab-in-suspension assays.

[0089] The present disclosure further describes a holder for holding the device herein, such as during the centrifugation operations. The holder allows one or more devices herein to be held securely in centrifuges during centrifugation.

[0090] Definitions

[0091] As used herein, each of the following terms has the meaning associated with it in this section. Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Generally, the nomenclature used herein are those well-known and commonly employed in the art. It should be understood that the order of steps or order for performing certain actions is immaterial, so long as the present teachings remain operable. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section. All publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference.

[0092] In the application, where an element or component is said to be included in and / or selected from a list of recited elements or components, it should be understood that the element or component can be any one of the recited elements or components and can be selected from a group consisting of two or more of the recited elements or components.

[0093] In the methods described herein, the acts can be carried out in any order, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0094] In this document, the terms "a," "an," or "the" are used to include one or more than one unless the context clearly dictates otherwise. The term "or" is used to refer to a nonexclusive "or" unless otherwise indicated. The statement "at least one of A and B" or "at least one of A or B" has the same meaning as "A, B, or A and B."

[0095] "About" as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20% or ±10%, in certain embodiments ±5%, in certain embodiments ±1%, in certain embodiments ±0.1% from the specified value, as such variations are appropriate to perform the disclosed methods.

[0096] As used herein, the term “top,” “bottom,” “upper,” “lower,” “above,” “below,” “upward,” “downward,” etc., when referring to positions of elements, surfaces of elements herein or directions, do not indicate the absolute positions / directions in the real world. Rather, these terms should be interpreted based on the drawings herein. For example, the an “upper surface” of an element is the surface which is higher than the “lower surface” of the same element in the direction of the vertical axis (z-axis) as shown in the figures. For another example, the term “downward” means a direction opposite to the direction of the z- axis.

[0097] Device

[0098] In some aspects, the present invention is directed to a device.

[0099] In some embodiments, the device arranges a plurality of fluid droplets according to a predetermined pattern, such as on a substrate of the device.

[0100] In some embodiments, some or all of the fluid droplets of the plurality of fluid droplets include a substance to be collected and a liquid. In some embodiments, the device collects the substance from the plurality of fluid droplets and / or according to the predetermined pattern. For example, the substance may be collected from the plurality of fluid droplets in the predetermined pattern on the substrate thereof.

[0101] In some embodiments, the device is configured to be centrifuged. In some embodiments, during the centrifugation, a centrifugal force is applied to the fluid droplets in a direction pointing roughly downwardly of the device.

[0102] Referring to Fig. 1A, in some embodiments, the device 100 includes a substrate 110, and a first patterned template layer 130 on and above the substrate 110.

[0103] In some embodiments, the substrate 110 holds the plurality of fluid droplets, and / or the substance collected from the fluid droplets, and the first patterned template layer 130 arranges the fluid droplets (and thereby the collected substance) according to the predetermined pattern. In some embodiments, the substrate 110 is configured to hold the substance, such as a liquid, a cell, or the like, that is being collected from the plurality of fluid droplets.

[0104] In some embodiments, the substrate 110 is a slide, such as a microscope slide. In some embodiments, the slide is charged and / or coated. In some embodiments, the slide is a Fisherbrand™ Superfrost™ Plus Microscope Slide (catalog no. 12-550-15) (which has a width of 25 mm and a length of 75 mm in accordance with some embodiments).

[0105] In some embodiments, the substrate 110 is coated. In some embodiments, the coating on the substrate 110 is hydrophilic, hydrophobic, and / or charged. In some embodiments, the coating on the substrate 110 functionalizes the coated area. In some embodiments, the entirety of the upper surface of the substrate 110 is coated. In some embodiments, only a portion of the upper surface of the substrate 110 is coated. In some embodiments, the substrate 110 is coated with more than one type of material having different properties (e.g., two or more of hydrophilic, hydrophobic, positively charged, or negatively charged). In some embodiments, the coating has a pattern. For example, in some embodiments, the substrate 110 is coated with a first material that retains the fluid droplets in areas in which the fluid droplets stay, and with a second material that expels the fluid in areas in which the fluid droplets are not supposed to be.

[0106] In some embodiments, the substrate 110 is coated with a poly-l-lysine. In some embodiments, the substrate 110 is coated with a poly-l-lysine solution (e.g., a 0.1 % (w / v) poly-l- lysine aqueous solution, such as that commercially available from Sigma Aldrich with product number P8920-100mL). In some embodiments, the charging and / or coating promotes adhesion between the plurality of fluid droplets and the substrate 100, thereby retaining the deposited droplets in specific areas of the substrate 110.

[0107] In some embodiments, the coating on the substrate 110 has a pattern. In some embodiments, the patterned coating allows the substrate 110 to retain the deposited fluid droplets at specific spatial locations. In some embodiments, the patterned coating creates channels for fluid to flow between spots.

[0108] In some embodiments, the first patterned template layer 130 is on and in direct contact with the substrate 110. In some embodiments, the device 110 further comprises a wick 120 (described elsewhere herein) sandwiched between and in direct contact with the substrate 110 and the first patterned template layer 130. In some embodiments, the first patterned template layer 130 has a plurality of apertures 132. In some embodiments, the plurality of apertures 132 are arranged according to the predetermined pattern such that the plurality of fluid droplets can be arranged on the substrate 110 with the same pattern.

[0109] In some embodiments, the apertures 132 extend through the thickness of the first patterned template layer 130. In some embodiments, the apertures 132 define regions through which the fluid can be introduced onto the substrate 110, thereby allowing the patterned array of fluid droplets to be formed. In some embodiments, a volume of the apertures 132 is calculated based on the thickness thereof in the z-direction and the lateral dimensions in the xy plane.

[0110] In some embodiments, a diameter (or an equivalent diameter in the case that the aperture 132 is not round along the xy plane) of the aperture 132 in the xy plane is about 1 mm, such as about 1.5 mm, about 2 mm, about 2.5 mm, about 3 mm, about 5 mm, about 8 mm, about 10 mm, about 15 mm, about 20 mm, or any ranges therebetween.

[0111] In some embodiments, the aperture 132 is sized to provide a droplet volume between about 0.5 pl and about 100 pl, such as between about 5 pl and about 50 pl, between about 8 pl and about 25 pl, or between 10 pl and 20 pl. In some embodiments, the aperture 132 is sized to provide a droplet volume of about 0.5 pl, about 1 pl, about 2 pl, about 5 pl, about 8 pl, about 10 pl, about 15 pl, about 20 pl, about 25 pl, about 50 pl, about 80 pl, about 100 pl, or any ranges therebetween.

[0112] In some embodiments, all or some of the apertures 132 are within a window area 134, which remains accessible when a second patterned template layer 150 (described elsewhere herein) is attached.

[0113] In some embodiments, the first patterned template layer 130 provides a template for holding the plurality of fluid droplets in place, such as before, during and after a centrifugation. In some embodiments, the first patterned template layer 130 provides an opening through which fluid flows, such as when the fluid is being collected or removed from the device via, e.g., a filter.

[0114] Additional descriptions of the first patterned template layer 130 are provided elsewhere herein. In some embodiments, the device 100 further comprises the wick 120 between the substrate 110 and the first patterned template layer 130. In some embodiments, the wick 120 is in direct contact with the substrate 110, the first patterned template layer 130, or both.

[0115] In some embodiments, the wick 120 has a plurality of openings 122. In some embodiments, the openings 122 in the wick 120 allow the fluid droplets in the first patterned template layer 120 to access the substrate 110. The sizes, shapes and / or patterns for openings 122 can be used / formed according to the design of the first patterned template layer 130.

[0116] In some embodiments, the locations of the openings 122 in the wick 120 correspond to the locations of the apertures 132 in the first patterned template layer 130. In some embodiments, each corresponding opening 122 and aperture 132 are concentric with each other.

[0117] In some embodiments, the wick openings 122 are of about same size as the apertures 132 on first patterned template 130. In some embodiments, the holes 122 are slightly larger than the apertures 132, such as about 1% larger, about 2% larger, about 5% larger, about 10% larger, about 20% larger, or about 50% larger in diameter. In some embodiments, the slightly larger holes 122 provide the space for capillary action, such as capillary action to remove the liquid from the fluid droplet.

[0118] In some embodiments, the wick 120 absorbs the liquid in the fluid droplets, thereby separating the liquid from the substance of interest on the substrate 110. In some embodiments, the wick 120 soaks up fluids between samples (fluid droplets) so that samples do not crosscontaminate. In some examples, the inclusion of the wick 120 allows the elimination of the coating / modification on the top surface of the substrate 110. In some embodiments, the wick 120 works in conjunction with the first template layer 130 to prevent the dispersion or spreading of fluids on the substrate 110.

[0119] The choice of material for the wick 120 is not limited. Non-limiting examples of materials for the wick 120 include filter paper or blotting paper, sponge, cloth, and the like. In some embodiments, the wick 120 is made from Whatman filter paper Grade 1 (with 0.30 mm thickness) or VWR® Blotting Paper, Grade 703 (catalog number 28298-028). Other materials, including but not limited to sponge, cloth, or the like, with different thicknesses can be used.

[0120] In some embodiments, without the application of the centrifugal force, surface tension alone is sufficient to retain the fluid droplets in the apertures 132. In some embodiments, the device 100 further comprises a filter layer 140 on and above the first template layer 130. In some embodiments, the filter layer 140 is in direct contact with the first template layer 130.

[0121] In some embodiments, the filter 140 holds the fluid droplets on an upper surface thereof when a centrifugal force is not applied. In some embodiments, the filter 140 sorts the substance in the fluid droplets according to a size of a mesh of the filter. In some embodiments, the filter 140 filters the fluid, removing large debris from the fluid and allowing liquid and smaller particles to pass through, land on the substrate 110, and form fluid droplets inside the apertures 132 or on substrate 110.

[0122] The material of the filter 140 is not limited. Non-limiting examples of materials of the filter 140 include nylon, polyester, polypropylene, poly ether ether ketone (PEEK), stainless steel, combinations thereof, or the like. In some embodiments, the material of the filter 140 is hydrophobic. In some embodiments, the material of the filter 140 is hydrophilic. In some embodiments, the material of the filter 140 is charged.

[0123] The thickness and mesh size of the filter 140 is not limited and can be chosen according to, e.g., the nature of the sample, the material and / or coatings of the substrate 110, the size and / or shapes of the apertures 132, the thickness of the second patterned template layer 150 (described elsewhere herein), and the like. In some embodiments, the thickness and / or mesh size of the filter 140 are chosen such that the fluid sample is retained on the upper surface of the filter 140 prior to the application of centrifugal force, and is allowed to pass through the mesh of the filter 140 to reach the lower side of the filter 140, such as to reach the apertures 132 and / or the upper surface of the substrate 110 during the application of the centrifugal force.

[0124] In some embodiments, a thickness of the filter 140 ranges from about 2 pm to 2000 pm, such as from about 5 pm to 1000 pm, from about 10 pm to 500 pm, from about 20 pm to 200 pm, or from about 50 pm to 100 pm. In some embodiments, the thickness of the filter 140 is about 2 pm, about 5 pm, about 10 pm, about 20 pm, about 50 pm, about 100 pm, about 200 pm, about 500 pm, about 1000 pm, about 2000 pm, or any ranges therebetween.

[0125] In some embodiments, a mesh size of the filter 140 ranges from about 2 pm to 2000 pm, such as from about 5 pm to 1000 pm, from about 10 pm to 500 pm, from about 20 pm to 200 pm, or from about 50 pm to 100 pm. In some embodiments, the mesh size of the filter 140 is about 2 gm, about 5 gm, about 10 gm, about 20 gm, about 50 gm, about 100 gm, about 200 gm, about 500 gm, about 1000 gm, about 2000 gm, or any ranges therebetween.

[0126] In some embodiments, the filter 140 is a nylon mesh filter having a thickness of about 70 gm and a mesh size of about 70 gm (e.g., Spectrum Laboratories product no. 145801).

[0127] In some embodiments, the filter 140 absorbs the liquid in the fluid sample. In some embodiments, the filter 140 does not absorb the liquid, or does not substantially absorb the liquid.

[0128] In some embodiments, the filter 140 is constructed from a material having resistance against corrosives, alkalis, organics, and / or acids. In some embodiments, the filter 140 has a pH resistance between pH values of about 2 and 14 or between about 3 and 10. In some embodiments, the filter 140 is considered to have pH resistance at a given pH value if the filter 140 is able to perform its intended function (e g., retaining fluid at either side thereof, filtering fluid, or the like) for 1 hour or more.

[0129] In some embodiments, the filter 140 has a thermal stability at about 130 °C or higher, such as about 150 °C or higher, about 160 °C or higher, about 180 °C or higher, about 200 °C or higher, about 230 °C or higher, or about 250 °C or higher, for 1 hour or more.

[0130] In some embodiments, the filter 140 is sterilizable by irradiation sterilization or autoclaving, without causing substantial damage to its intended function.

[0131] In some embodiments, the device 100 further comprises a second patterned template layer 150 on and above the first patterned template 130. In some embodiments, the second patterned template layer 150 is in direct contact with the first patterned template 130. In some embodiments, the second patterned template layer 150 is above and in direct contact with the filter 140.

[0132] In some embodiments, the second patterned template layer 150 has a window area 154. In some embodiments, the window area allows the visual inspection and / or access of some or all of the apertures 132 in the first patterned template 130.

[0133] In some embodiments, the second patterned template layer 150 provides a thickness to the stack of layers in device 100 without touching or interfering with the fluid samples. In some embodiments, a thickness of the second patterned template layer 150 is equal to or larger than a height of the fluid droplets formed on either the optional filter 140 or a height of a portion of the fluid droplets in the apertures 132 that is above the upper surface of the first patterned template layer 130, such that the stacking of any subsequent layer, if any, does not interact with the fluid droplets.

[0134] In some embodiments, the second patterned template layer 150 stabilizes the stack so that the sections fit together without bulges or gaps. In some embodiments, the second pattern template layer 150 facilitates the introduction of the fluid into the lower (underlying) layers, such as the substrate 110, the first patterned template layer 130, the wick 120, and the filter 140.

[0135] In some embodiments, the second patterned template layer 150 comprises features on a lower surface thereof that can retain the optional filter 140 layer in place.

[0136] Additional descriptions of the second patterned template layer 150 are provided elsewhere herein.

[0137] In some embodiments, the device further comprises a lid 160 on and above the first patterned template layer 130. In some embodiments, the lid 160 is in direct contact with the second patterned template layer 150 (if present), in direct contact with the filter 140 (if present and the second patterned template layer 150 is not present), or in direct contact with the first pattern template layer 130 (if both the filter 140 and the second patterned template layer 150 are absent).

[0138] In some embodiments, the lid 160 tops off the stack of layers of the device 100, and prevents fluid loss. In some embodiments, the lid 160 provides a surface for screws, clips, and / or clamps to attach to the device 100 without disrupting the sample collection area as defined by the substrate 110, the aperture 132, the optional openings 122, and the optional window area 154. In some embodiments, the lid 160 provides a mechanical structure that allow the device 100 to be placed into a centrifuge.

[0139] The material for making the lid 160 is not limited. In some embodiments, the lid 160 is a glass lid, a metal lid, a plastic lid, a polymer lid, or the like. In some embodiments, the lid 160 is a glass microscope slide with the same size as the microscope slide used for substrate 110. In some embodiments, lid 160 is formed using the same materials as the patterned template layers 130 and / or 150.

[0140] In some embodiments, the device 100 further comprises a stretch film (such as a polyolefin-based film like parafilm), a screw, a clip, and / or a clamp for securing the layers of the device 100 together and keeping the proper alignment of the layers. In some embodiments, all the layers of the device 100 are mechanically clipped together using a stretch film, a screw, a clip (e.g., a glass clip), a clamp, and the like. One example of the glass clip is those made by the Guangzhou Open Find Electronic Commerce Co, LTD, with the catalog number A170826WQ001. This clip is a zinc alloy rectangle adjustable clip clamp, with an internal bracket holder to support a device between 6- 10mm thickness.

[0141] In some embodiments, elements for securing and aligning the layers of the device 100 are built into the first patterned template 130, the second patterned template 150, and / or the lid 160. In some embodiments, elements for securing and aligning the layers of the device 100 are built into the lid 160.

[0142] In some embodiments, the lid 160 comprises features that allow lid 160 to mechanically combine with the substrate 110, thereby securing all the layers sandwiched between the lid 160 and the substrate 110, without the need for a screw / clip / clamp. In some embodiments, the lid 160 is mechanically combinable with the first patterned template layer 130, the second patterned template layer 150, the wick 120 and / or the filter 140 (provided that these layers are part of the device 100).

[0143] Referring to Fig. 19, a non-limiting example of the lid 1900 is shown. In some embodiments, the lid 1900 comprises a base 1902, sidewalls 1904, and retaining features 1906. In some embodiments, the lid 1902 slides over the previously-combined structure (e.g., the substrate, the patterned template layer(s), the wick, and the filter), and secures all the layers in a properly aligned state.

[0144] Referring back to Fig. 1A, in some embodiments, the device 100 comprises the substrate 110, the wick 120 (optional), the first patterned template layer 130, the filter 140 (optional), the second patterned template layer 150 (optional), and the lid 160 (optional) from bottom to top in this order, and each of the layers is in direct contact with the adjacent layer(s). For example, for a device 100 that comprises substrate 110, the first patterned template layer 130, and the lid 160 but does not comprise the wick 120 or the filter 140, the substrate 110 at the bottom is in direct contact with the first patterned template layer 130 in the middle, and the first patterned template layer 130 in the middle is also in direct contact with the lid 160 on the top.

[0145] Referring to Fig. IB, in some embodiments, the device 100’ further comprises a funnel 170’ inserted into the aperture 132’ of the first patterned template layer 130’. In some embodiments, the funnel 170’ extends beyond an upper surface (relative to the direction of the z- axis) of the first patterned template layer 130’ or a lower surface (relative to the direction of the z-axis) of the first patterned template layer 130’

[0146] In some embodiments, the funnel 170’ is fabricated as a part of the first patterned template layer 130’. In some embodiments, the funnel 170’ is a separate element from the first patterned template layer 130’ and aligns with the apertures 132’.

[0147] In some embodiments, the maximum volume the funnel 170’ is able to hold is about 10 pl, about 20 pl, about 50 pl, about 100 pl, about 200 pl, about 500 pl, or about 1000 pl. In some embodiments, the inclusion of the funnel 170’ allows the first patterned template layer 130’ to hold larger volume of fluid than in the case where the funnel 170’ is absent.

[0148] First patterned template layer

[0149] Referring to Figs. 2A and 2B, in some embodiments, the first patterned template layer 200 has an upper surface 202, and a lower surface 204. A thickness of the first patterned template layer 200 in the z direction is Z200. The first patterned template layer 200 has a first dimension X202 and a second dimension y202. first patterned template layer 200 has a plurality of apertures 206 that extend through the thickness of the substrate. The apertures 206 have a dimension X206 and y206 in the plane of the upper and lower surfaces.

[0150] In some embodiments, the plurality of apertures 206 is in a window region 208, which has dimensions dimension X208 and y2os. The first patterned template layer 200, the window region 208, and the plurality of apertures 206 can have any dimension and / or shape. The location as well as the dimensions in the x-y plane of the window region 208 is configured depending on the imaging tool that is to be used.

[0151] Figs. 3A and 3B illustrate another configuration of the first patterned template layer 300, which is similar to that of the first patterned template layer 200, but with the addition of alignment features 310a, 310b, 310c, and 3 lOd to assist in the alignment of the template with layers above or below the first patterned template layer 300 (e.g., substrate, wick, filter, lid, etc.).

[0152] As shown in Figs. 3A and 3B, the alignment features 310a and 310c are along one of the longitudinal edges of the template 300, and the alignment features 310b and 3 lOd are along the two lateral edges. The alignment features 310a-3 lOd have a thickness t2io greater than the thickness tsoo of the first patterned template layer 300, to facilitate the alignment of the first patterned template layer 300 with other layers of the device herein. One of ordinary skill in the art, reading in light of the instant specification, would understand that the shape and placement of the alignment features are not limited and there are many ways to configure the alignment features to facilitate the alignment of the layers.

[0153] For example, Figs. 4A and 4B illustrate another configuration of the first patterned template layer 400, with a set of alignment features 401a, 401b and 401c.

[0154] Figs. 5A and 5B illustrate yet another configuration of the first patterned template layer 500 having yet another set of alignment features 510a and 510b.

[0155] The first patterned template layer can be made of any suitable material. In some embodiments, the first patterned template layer is made from glass, stainless steel, polytetrafluoroethylene (Teflon), nylon, a plastic or a polymeric material, a poly-lactic acid (PLA), a PEEK, or combinations thereof.

[0156] In some embodiments, the first patterned template layer is formed using an additive manufacturing (such as a 3D printing), which is able to create the apertures in the manufacturing process. In some embodiments, the apertures are made by machining an un-patterned sheet of material. In some embodiments, the first patterned template layer is formed using injection molding.

[0157] In some embodiments, a combination of the material type and the thickness of the material provides sufficient rigidity to the first patterned template layer, such as allowing the upper and lower surfaces thereof to remain flat during production and / or use.

[0158] The first patterned template layer may be of any shape, size, and / or dimensions. In some embodiments, the first patterned template layer is sized to match the other layers of the device, such as the substrate, the lid, etc, in the xy plane. In some embodiments, the first patterned template layer has dimensions in the xy plane that match a rectangular microscope slide, which can be used as the substrate and / or the lid. For example, if a Fisherbrand™ Superfrost™ Plus Microscope Slide (catalog no. 12-550-15) with a width of 25 mm and a length of 75 mm is used as the substrate and / or lid, the width and length of the first patterned template layer can be 25 mm and 75 mm, respectively.

[0159] Referring to Figs. 6 and 7, in some embodiments, the first patterned template layer is square or circular in the xy plane.

[0160] In some embodiments, the window region, which is defined by the instrumentation with which the substrate-to-be-patterned will be used, takes any shape that fits within the area of the substrate surface. As shown in Figs. 2A, 2B, 3 A, 3B, 4A, 4B, 5A, 5B, 6, 7, and 8, the window region (indicated by a dashed line) can be rectangular, square, or circular, though other shapes may be used according to the instrumentation used to analyze the droplets on the slide.

[0161] It is worth noting that the apertures of the first patterned template layer do not have to be round in the xy plane, and that the window region does not have to be rectangular; rather, they can take any shape. Referring to Fig. 8, the first patterned template layer 800 has square apertures 806 that fit within a circular window 808.

[0162] It is worth noting that the alignment features can extend beyond one or both of the surfaces of the first patterned template. In Figs. 2A, 2B, 3A, 3B, 4A, 4B, 5A, and 5B, the alignment features extend above one of the two surfaces of the first patterned template only. As shown in Fig. 9, in the first patterned template layer 900, the alignment features 910 extends beyond both the lower surface 904 and the upper surface 902 (t9io > t9oo).

[0163] In some embodiments, the first patterned template layer has features on the upper surface thereof that allows the retention of the optional filter layer in place. In some embodiments, these features could include internal clamps within the layer, interlocking pieces between layers, protrusions, designs that support a taut filter layer, or the like.

[0164] In some embodiments, the xy plane cross-sections of an aperture in the first patterned template layer do not have the same size and / or shape along the vertical direction (the z-axis) (i.e., having an “irregular shape”). In some embodiments, the first patterned template layer, in the regions near the apertures, comprises guide structures that extend beyond one or both of the surfaces of the first patterned template layer.

[0165] In some embodiments, the irregular shape of the aperture and / or the guide structures provides better confinement of fluid droplets as they are formed on the substrate below. In some embodiments, the irregular shape of the aperture and / or the guide structures provides better confinement of the fluid in the aperture that extends beyond a level of the upper surface of the first patterned template layer and prevents leakage and / or spreading of fluid across separating regions between the apertures.

[0166] Referring to Fig. 13, a cross-section of an embodiment of the first patterned template layer 1300 is shown. In the first patterned template layer 1300, a plurality of apertures 1306 are arranged inside a window region 1308, which has a dimension of XBOS in the x-direction. Each of the apertures 1306 has a first dimension xi306a at an upper surface 1302 of the first patterned template layer 1300, and a second dimension xi306b at the lower surface 1304.

[0167] In some embodiments, the first dimension xi306a is larger than the second dimension xi306b. In some embodiments, the apertures 1306 have a funnel shape, such as a circular conical funnel shape. In some embodiments, the funnel shape allows the fluid to be held at a top side of the aperture 1306 by surface tension before application of the centrifugal force, while also allowing the fluid to move to the bottom side of the aperture 1306 when the centrifugal force is applied. In some embodiments, the funnel design allows for more fluid to be deposited within the layer. Any shape of the funnel in both the xy plane and in the z direction may be chosen to control the fluid delivery. In some embodiments, the cross-section of the aperture at the xy plane may have a circular shape, a square shape, a rectangular shape, an elliptical shape or any other shape. In some embodiments, in the z-direction, the lateral or longitudinal dimension changes linearly (e.g., a conical funnel shape in the xz or yz plane) or non-linearly (e.g., an hourglass shape in the xz or yz plane). In some embodiments, the apertures 1306 have regions where the lateral / longitudinal dimension is varying in the z-direction, and regions where the lateral / longitudinal dimension is fixed in the z-direction.

[0168] Referring to Fig. 14A, in some embodiments, the first patterned template layer 1400 comprises, near the apertures 1406 (such as funnel shaped aperture 1406), retaining protrusions 1412 above an upper surface 1402. In some embodiments, the retaining protrusions 1414 confine a deposited fluid in apertures 1406 above a level of the lower surface 1404, such that the fluid does not spread between adjacent apertures 1406.

[0169] Referring to Fig. 14B, in some embodiments, the first patterned template layer 1400’ comprises, near the apertures 1406’ (such as funnel shaped aperture 1406’), protrusions 1414’ below surface 1404’. In some embodiments, the protrusions 1414’ confine deposited fluid on the underlying substrate directly under aperture 1406, preventing spreading.

[0170] Referring to Fig. 15, two non-limiting examples of the first patterned template layers 1600 and 1650 are shown. The exemplary first patterned template layers are 3D printed using PLA. Each first patterned template layer is approximately 3mm thick. The apertures in 1600 are approximately 3 mm in diameter, and the apertures in 1650 are approximately 6 mm in diameter. Alignment marks are nominally 3.75 mm thick. The apertures fit within the window region of the second template layer (1700, shown in Fig. 16). Openings in an underlying (optional) wick layer are concentric with the apertures in the first patterned template layers. The openings are the same size as, or larger than the aperture sizes in the first patterned template layer. Where the aperture dimension varies in the z-direction, the opening is the same as or larger than the dimension of the aperture where it is in contact with the wick layer.

[0171] Second patterned template layer

[0172] Referring to Figs. 10A and 10B, in some embodiments, the second patterned template layer 1000 is sized identically with the first patterned template layer, so that the two patterned temple layers can be aligned.

[0173] In some embodiments, the two patterned template layers are aligned using alignment marks.

[0174] In some embodiments, the two patterned template layers are aligned through alignment features incorporated into at least one of the first and second patterned template layers to facilitate their alignment and integration. In some embodiments, the alignment features include a clip or a “runner” that allows one layer to slide over or under the other.

[0175] In some embodiments, the second patterned template layer 1000 has a window region 1008, which is sized the same as or larger than the window region of the first patterned template layer (such as the window region 134 of the first patterned template layer 130 as shown in Fig. 1A). In some embodiments, the window region 1008 allows the access of some or all of the apertures of the first patterned template layer.

[0176] Referring to Fig. 11, an example of the second template layer 1000 comprising additional alignment features is shown. The location of the alignment features on the second patterned template layer 1000 is not limited and is the same as or similar to those as described for the first patterned template layer in some embodiments.

[0177] Referring to Fig. 12, an example of the second patterned template layer 1200 that is compatible with the first template layer 600 of Fig. 6 is shown. As opposed to an open window, the second patterned template layer 1200 of Fig. 12 is patterned with an array of holes 1206 that fit within window area 1208. The size (e.g., diameter or equivalent diameter) of the apertures 1206, di206, is chosen to be equal to or greater than the size (diameter or equivalent diameter) of the apertures 606 (d606) in the first patterned template layer 600 shown in Fig. 6. In some embodiments, the apertures 1206 of Fig. 12 and the apertures 606 of Fig. 6 are concentric when the two patterned template layers are properly aligned, and the size of the apertures 1206 in the second patterned template layer 1200 is equal to or larger than the size of the apertures 606 in the first patterned template layer 600.

[0178] The shapes and profiles of the apertures in the second patterned template layer are not limited, as long as they are compatible with the apertures in the first patterned template layer.

[0179] The thickness of the second patterned template layer is not limited, as long as such a thickness is sufficient to provide rigidity. One of ordinary skill in the art would be able to determine the thickness based on the material used for constructing the second patterned template layer, as well as the shape, size, number and arrangement of cut-out sections, such as the window region or the aperture in the second patterned template layer.

[0180] In some embodiments, the manufacture of the second patterned template layer is similar to that of the first patterned template layer, which is described elsewhere herein.

[0181] Referring to Fig. 16, two non-limiting examples of the second patterned template layers 1700 and 1750 are shown. The two second patterned template layers 1700 and 1750 are 3D printed using PLA. Each second patterned template layer is approximately 3mm in thickness. The window size in the second patterned template layer 1700 is approximately 18 mm by 34.9 mm, which corresponds to an optical measurement area of a particular analysis tool (this analysis tool is not considered part of the device herein), and the window size in the second patterned template layer 1750 is approximately 21 mm by 37 mm.

[0182] Method

[0183] In some aspects, the present invention is directed to a method of processing a sample with the device herein.

[0184] In some embodiments, the method comprises loading a fluid sample onto the device.

[0185] In some embodiments, the device does not comprise the filter, and the fluid is loaded directly into the apertures of the first patterned template layer.

[0186] In some embodiments, the device comprises the filter, and the fluid is loaded on an upper side of the filter opposite to the first patterned template layer. In some embodiments, the fluid passes through the filter and enters the aperture in the first patterned template layer without the application of a centrifugal force. In some embodiments, surface tension holds the fluid droplets on the filter and a centrifugal force is applied before the fluid droplets pass through the filter and enter the aperture in the first patterned template layer.

[0187] In some embodiments, the fluid droplets on the filter or in the apertures of the first patterned template layer are settled on an upper surface of the substrate, via gravity, charge- charge / hydrophilic / hydrophobic interaction between the fluid droplet and the substrate, and / or the application of a centrifugal force.

[0188] In some embodiments, the method further comprises drying the fluid droplets transferred to the substrate. The method of drying the fluid droplets is not limited. In some embodiments, the substrate is subjected to a flow of air or a temperature at least 20 degrees Celsius above room temperature. In some embodiments, the wick between the substrate and the first patterned template layer removes all or a part of the liquid in the fluid droplet.

[0189] Figs. 17A-17C illustrate a non-limiting example of the method herein.

[0190] Referring to Fig. 17A, fluid droplets were applied on a non-limiting first patterned template layer having a 5 x 8 array of apertures by pipetting, and were held in the apertures by the surface tension alone.

[0191] Referring to Fig. 17B, the fluid droplets were transferred onto the surface of the substrate (a microscope slide having a frosted region) by stacking the first patterned template layer of Fig. 17 on top of the substrate, and applying a centrifugal force downwardly. As shown in Fig. 17B, the fluid droplets were confined to the substrate in regions under the apertures, with no observable spreading or cross-contamination.

[0192] Referring to Fig. 17C, the array of fluid droplets shown in Fig. 17B were dried by placing the substrate on a slide warmer of about 65 °C for about one hour. After drying, an array of solid substance spots was formed on the substrate, which can be subjected to further analysis. For example, in the case that the fluid droplets are saliva samples from subjects, the solid substance spots can be stained with antibodies or dyes for specific types of immune cells, enabling the identification and counting of the immune cells present in the saliva samples.

[0193] Figs. 18A-18F illustrate another non-limiting example of the method herein.

[0194] Referring to Fig. 18A, a non-limiting device according to some embodiments herein comprises a substrate, a wick, a first patterned template layer with apertures, a filter, a second patterned template layer with a window region, and a lid. Referring to Fig. 18B, the layers of the non-limiting device, apart from the lid, were assembled using parafilm as a fastening mean.

[0195] Referring to Fig. 18C, droplets of fluid samples were introduced onto the filter at locations corresponding to the apertures in the first patterned template layer with a pipette, which accessed the filter through the window region of the second patterned template. Due to surface tension, the fluid droplets are held on the filter.

[0196] Referring to Fig. 18D, the lid was placed on top of the assembly of Fig. 18C.

[0197] Referring to Fig. 18E, a clip with screws was used to secure the layers together.

[0198] Referring to Fig. 18F, the assembly of Fig. 18E was place in a centrifuge, which can apply a centrifugal force to the assembly and settle the fluid droplets on the bottom substrate layer.

[0199] Sample Restraining Modules and Devices Using the Same

[0200] In some embodiments, rather than relying on the first patterned template layer having the apertures (described elsewhere herein) to define the spots where the fluid droplets are going to be formed on the substrate, one or more sample restraining modules (such as sample restraining modules 190 or 195 shown in Figs. 20A and 20B, respectively) are used instead.

[0201] Sample restraining module

[0202] Referring to Fig. 20A, in some embodiments, the sample restraining module 190 has an upper opening 191, a lower opening 192, and a passage 193 connecting the two openings. Such configuration allows the sample to be loaded into the upper opening 191, move downward along the passage 193 either by gravity or the application of a centrifugal force, and settle at the lower opening 192, which is in proximity with the substrate. This way, the sample loaded into the sample restraining module 190 can settle on the substrate and form a fluid droplet in a size / shape similar to the lower opening 192.

[0203] Using the sample restraining module 190 to form the fluid droplets on the substrate has several advantages. For example, the sample restraining module 190 can be made much smaller than the first patterned template layer. As such, the sample restraining module 190 can be configured such that they can be adhered or fused to the substrate temporarily before the samples are being loaded, remain one piece with the substrate when the device is being subjected to a centrifugal force, and be removed with relatively easy when the centrifugation is complete. This way, leakage along the xy plane on the upper surface of the substrate can be substantially reduced or even entirely eliminated. Furthermore, the use of the sample restraining module 190 eliminates the direct contact between the sample and the first patterned template layer. As such, the first patterned template layer does not need to contact the sample and become contaminated. This way, the first patterned template layer can be reused without thorough cleaning procedures.

[0204] Referring to Fig. 20A, in some embodiments, the sample restraining module 190 is a hollow columnar structure, such as a hollow cylinder. It is worth noting that the sample restraining module 190 does not have to be cylindrical as suggested by Fig. 20A. Rather, as long as the sample restraining module 190 has the top opening 191 for sample loading, the bottom opening 192 for the loaded sample to settle on the substrate (such as the substrate 110” of Fig. 21) without substantial leakage during the application of a downward centrifugal force, and a passage 193 fluidly connecting the two openings, the configuration of the sample restraining module 190 is considered to be within the scope of the instant specification.

[0205] In some embodiments, the sample restraining module 190 includes an adhesive on a bottom surface thereof. According to this embodiment, the sample restraining module 190 can adhere to the substrate, thereby sealing off any gaps between the lower opening 192 and the substrate and preventing leakage of sample during the centrifugation.

[0206] The materials for constructing the sample restraining module 190 are not limited. Virtually all materials that do not affect the sample (such as do not react with or contaminate the sample) and can hold the sample within without leaking can be used. In some embodiments, the sample restraining module 190 is constructed from a thermoplastic. Thermoplastics, such as low- density polyethylene (food-grade plastic), become softened and sticky when subjected to an elevated temperature, and fuse with the substrate at the lower opening 192 and seal off any gaps to prevent leakage during centrifugation. As such, construction of the sample restraining module 190 using thermoplastics allows the elimination of the adhesive.

[0207] Fig. 20B shows an alternative embodiment of the sample restraining module 195, which is similar to the sample restraining module 190 of Fig. 20A but further includes a filter 198. According to this embodiment, the sample loaded into the sample restraining module 195 would move downwardly during the application of the centrifugal force, passing through the filter 198, and settle on the substrate in a spot defined by the lower opening of the sample restraining module 195.

[0208] In some embodiments, the sample restraining module 195 includes an upper portion 196 and a lower portion 197 stacked vertically, as well as a filter 198 sandwiched therebetween.

[0209] In some embodiments, one or both of the upper portion 196 and the lower portion 197 are the same as or similar to the sample restraining module 190 shown in Fig. 20A. In some embodiments, a lower opening of the upper portion 196 is aligned with an upper opening of the lower portion 197 such that the internal passages of the upper portion 196 and the lower portion 197 are continuous.

[0210] In some embodiments, the filter 198 of the sample restraining module 195 is the same as or similar to the filter described elsewhere herein, such as the filter 140 of Fig. 1A, apart from having a smaller dimension on the xy plane to accommodate the smaller size of the sample restraining module 195.

[0211] Device including sample restraining module

[0212] Referring to Fig. 21, in some embodiments, the device 100” includes, from bottom to top, a substrate 110”, an optional wick 120” having one or more openings 122”, an optional first patterned template layer 130” having a window region 134”, one or more sample restraining modules 190” or sample restraining modules 195”, an optional second patterned template layer 150” having a window region 154”, and an optional lid 160”.

[0213] In some embodiments, the substrate 110” is the same as or similar to the substrates described elsewhere herein, such as the substrate 110 of Fig. 1A. In some embodiments, the substrate 110” is coated with a coating that allows the sample restraining modules 190” or 195” to both fuse or adhere to the substrate 110” and removed mechanically (such as by using a pair of tweezers). As describe elsewhere herein, since the sample restraining modules 190” or 195” are sometimes made from thermoplastics and are fused to the substrate 110” by heating up the sample restraining modules 190” or 195”, in some embodiments, the substrate 110” is coated with poly-L-lysine, fibronectin, collagen, or other materials that promotes the adhesion.

[0214] In some embodiments, the optional wick 120” is the same as or similar to the wicks described elsewhere herein, such as the wick 120 of Fig. 1A. In some embodiments, the wick 120” has one or more openings 122” that align with the sample restraining modules 190” or 195” such that the bottom surface of the sample restraining modules can be in direct contact with the substrate 110” through the openings 122” to allow the adhesion / fusion between the sample restraining modules 190’7195” and the substrate 110”.

[0215] It is worth noting that, since the adhesion / fusion between the sample restraining modules 190’7195” and the substrate 110” can securely immobilize the sample restraining modules 190’7195” on the substrate 110”, in some embodiments, both the first patterned template layer 130” and the second patterned templated layer 150”, whose roles are to restrain the modules 190” or 195” during the centrifugation, can be eliminated from the device 100”. (see e.g., Figs. 24A-24F).

[0216] In some embodiments, the sample restraining modules 190” or 195” are the same as or similar to those described elsewhere herein, such as in Figs. 20A and 20B.

[0217] In some embodiments, the optional first patterned template layer 130” and the optional second patterned template 150” are the same as or similar to those described elsewhere herein, such as the first / second patterned template layer described in Figs. 1 A, 2A-2B, 3A-3B, 4A-4B, 5A-5B, 6-9, 10A-10B, 11-13, 14A-14B, and 15-16. It is particularly worth noting that the first patterned template layer 130” can be the same as those for the second patterned template described elsewhere, and the second patterned template layer 150” can be the same as those for the first patterned template described elsewhere. The reasons are that, in the device 100”, the sample restraining modules 190” or 195”, rather than the first patterned template layer 130”, are responsible for defining the regions for forming the fluid spots. The functions of the first patterned template first patterned template layer 130” and the optional patterned template layer 150” become, among others, holding the sample restraining modules 190” or 195” before and during the sample restraining modules 190” or 195” are being coupled to the substrate, and providing structural support in the device 100”, such as structural support for the sample restraining modules 190” or 195” during the centrifugation. As such, the shape and size of the openings / window regions 134” and 154” are chosen according to the size of the sample restraining modules 190” or 195”, and configurations previous described for various first / second patterned template layer are all applicable to the first patterned template layer 130” and the optional patterned template layer 150”.

[0218] For example, Figs. 22A and 22B show two configurations for the first / second patterned template layers 2202 and 2202’. Referring to Fig. 22A, in some embodiments, the first / second patterned template layer 2202 has a window region 2208, which allows a plurality of sample restraining modules 2212 to fit in. Referring to Fig. 22B, in some embodiments, the first / second patterned template layer 2202’ has a plurality of openings 2206’ in a window region 2208’, each of which can accommodate one sample restraining module 2212’.

[0219] Referring back to Fig. 21, in some embodiments, whether to include the second patterned template 150” in the device 100” depends on the height of the sample restraining modules 190” or 195”. If the height of the sample restraining modules 190” or 195” is larger than the thickness of the first patterned template layer 130”, the second patterned template layer 150” is required if the optional lid 160” is also required. In some embodiments, the height of the sample restraining modules 190” or 195” is larger than the sum of the thickness of the first patterned template layer 130” and the thickness of the second patterned template layer 150”, a one more similar patterned template layer(s) (not shown) can be included.

[0220] It is also worth noting that, since in device 100”, the sample restraining modules 190” or 195” is securely coupled to (such as fused with or adhered to) the substrate before the application of centrifugal force according to some embodiments, the first / second patterned template layer 130’7150”, as well as the lid 160” are optional during the centrifugation process. As such, in some embodiments, the device 100” herein does not include the first / second patterned template layer 130’7150” and / or the lid 160”.

[0221] In some embodiments, the lid 160” is the same as or similar to the lids described elsewhere herein, such as the lid 160 of Fig. 1A or the lid 1900 of Fig. 19.

[0222] In some embodiments, the device 100” further includes one or more elements described elsewhere herein, which is not shown in Fig. 21.

[0223] Method of using device including sample restraining module

[0224] Methods of using the device including the sample restraining module is generally the same as that of using the device which uses the first patterned template layer to define fluid spots described herein. The only difference is that the sample restraining module(s) needs to be mounted on and coupled to the substrate, the sample is loaded into the sample restraining module(s), and that the sample restraining module(s) is removed from the substrate after the formation of the fluid spots. Referring to Fig. 23, in some embodiments, one or more sample restraining module(s) is mounted on the upper surface of the substrate in a void defined by the window region in the first / second patterned template layer(s).

[0225] The sample restraining module(s) is then coupled to the substrate. In the non-limiting embodiment, where the sample restraining module(s) is made from food-grade low-density polyethylene, the assembly is subjected to three cycles of an elevated temperature of about 210 °C for 30 seconds plus cooling down to room temperature, thereby fusing the lower surface of the sample restraining module(s) with the upper surface of the substrate.

[0226] Samples (in this case cells suspended by a cell adhesion medium or CAM, such as a saliva, an artificial saliva, or another medium containing mucins or other viscosity control agents to suspend the cells evenly) are loaded into the sample restraining module(s) via the upper opening thereof. The device is then centrifuged to settle the fluid spots of the samples on the substrate. The sample restraining module(s) is then removed from the substrate, such as by a mechanical force, to expose the array of fluid spots.

[0227] When sample restraining modules herein are used in the device herein, since the sample restraining modules can be adhered or fused to the substrate securely without the aid of the two patterned template layers, the device can be functional without the patterned template layers.

[0228] Referring to Figs. 27A-27E, in some embodiments, the method comprises loading samples into sample restraining modules mounted on the substrate (Fig. 27B). The lid is mounted on top of the sample restraining modules and the substrate (Fig. 27C). A clamp with screws is then used to clamp the substrate, the sample restraining modules, and the lid, thereby completing the device (Figs. 27D-27E). The device is then centrifuged, allowing the sample inside the sample restraining modules to settle on the substrate, and forms a patterned array of fluid droplets according to the arrangement of the sample restraining modules. The sample restraining modules are then removed from the substrate, revealing the patterned array of fluid droplets, (see Figs. 27F-27K).

[0229] Holder

[0230] In some aspects, the present invention is directed to a holder, or slide adapter assembly.

[0231] In some embodiments, the holder is adapted and configured to hold any suitable device or article for depositing and / or analyzing samples. Suitable devices / articles include, but are not limited to, slides, slide assemblies, plates, microplates, any of the articles / devices according to one or more of the embodiments, any other suitable article for depositing and / or analyzing samples, or a combination thereof. In some embodiments, the holder is configured to hold one or more of the articles for depositing and / or analyzing samples therein securely before, during, and / or after a centrifugation operation. For example, the holder may be configured to hold at least one article, at least two articles, at least three articles, at least four articles, between one and four articles, between two and four articles, or any suitable combination, sub-combination, range, or sub-range thereof. In some embodiments, the holder is configured to hold between two and four articles therein.

[0232] In some embodiments, the holder is configured to fit into a centrifuge, such as a swinging bucket centrifuge and / or an existing plate holder, with or without the one or more articles positioned therein. Centrifuge plate holders designed to hold microplates (e.g., a 6-well, 12-well, 24-well, 48-well, 96-well, or 384-well plate) are widely available commercially. Accordingly, in some embodiments, the holder herein includes dimensions similar to those of a standard microplate and / or is otherwise configured to fit in existing centrifuge plate holders, such as those that hold 127.76 mm x 85.48 mm microplates. For example, in some embodiments, the entirety or some of the dimensions of the holder herein is the same as or similar to (such as ±0.1%, ±0.2%, ±0.5%, ±1%, ±2%, ±5%, or ±10%) those of a standard microplate, which are set forth in “ANSI / SLAS 1-2004: Microplates — Footprint Dimensions,” “ANSI / SLAS 2-2004: Microplates — Height Dimensions,” “ANSI / SLAS 3-2004: Microplates — Bottom Outside Flange Dimensions,” “ANSI / SLAS 4-2004: Microplates — Well Positions,” and “ANSI / SLAS 6-2012: Microplates — Well Bottom Elevation” published by the SLAS Microplate Standards Advisory Committee.

[0233] In some embodiments, multiple holders may be configured to fit within a centrifuge at the same time and / or in combination with one or more microplates or other centrifuge elements. As such, the holder(s) according to one or more of the embodiments disclosed herein can individually and together hold a plurality of devices / articles in a centrifuge at one time. Therefore, in some embodiments, the holder(s) are capable of forming fluid droplets and / or a patterned array of fluid droplets on each device / article of a plurality of the devices / articles during a single centrifugation. In some embodiments, the holder(s) facilitate forming of fluid droplets and / or a patterned array of fluid droplets uniformly across the plurality of the devices / articles held in the one or more holders during centrifugation.

[0234] Some centrifuge microplate holders hold microplates by the bottom surface or the bottom outside flange. Accordingly, in some embodiments, the dimensions of the bottom surface / bottom outside flange of the holder described herein are the same as or similar to those of a microplate.

[0235] Some centrifuge microplate holders hold microplates by the side walls thereof. Accordingly, in some embodiments, the dimensions of the side walls of the holder herein are the same as or similar to those of a microplate.

[0236] Referring to Fig. 24, in some embodiments, the holder 2300 comprises an optional holder base 2310, a holding tray 2330, and an optional holder lid 2350.

[0237] In some embodiments, the optional holder base 2310 supports the holding tray 2330 and provides a bottom surface (and / or a bottom portion of a side wall) having the same or similar dimensions to those of a microplate, such that centrifuge plate holders that hold microplates by the bottom portion are able to hold the holder 2300, as well. In some embodiments, the holder base 2310 has a bottom outside flange that is the same as or similar to that of a standard microplate. Alternatively, in some embodiments, the holding tray 2330 includes a bottom surface and / or bottom outside flange configured to be held directly by a centrifuge microplate holder. Accordingly, in some such embodiments, the holder 2300 may not include the holder base 2310.

[0238] In some embodiments, the holding tray 2330 includes a side portion 2331 and an aligner portion 2335. The side portion 2331 provides structural rigidity in the lateral directions and / or provides the holder 2300 with the desirable height, while the aligner portion 2335 includes one or more slots 2337 for hosting the articles / devices for depositing and / or analyzing samples (such as the devices described herein, such as in the “Device” and “Sample Restraining Modules and Devices Using the Same” sections). The side portion 2331 and the aligner portion 2335 may be attached or integrally formed (z.e., the holding tray 2330 is one piece), or the side portion 2331 and the aligner portion 2335 may be separate (i.e., the holding tray 2330 is multiple pieces). In multiple-piece configurations, the aligner portion 2335 may be configured to removably sit within the side portion 2331, resting and / or being removably secured on a bottom surface of the side portion 2331 or the holder base 2310. Additionally or alternatively, in some embodiments, the one-piece holding tray 2330 or the aligner portion 2335 of the multiple-piece holding tray 2330 may be interchangeable in the holder 2300, such that different holding trays or aligner portions may be selected based upon the specific devices / articles being held.

[0239] In some embodiments, the one or more slots 2337 include a shape adapted and configured to receive the articles / devices (e.g., an inner perimeter of each slot mirrors an outer perimeter of an article / device). For example, according to some embodiments, the device herein has a shape of roughly a rectangular cuboid. Accordingly, in some embodiments, the slots 2337 are configured to host rectangular cuboid shaped objects in general. It should be noted that, the shape of the one or more slots 2337 is not limited to accommodating the rectangular cuboid shape, as the shapes of devices for forming fluid droplets are not limited thereto. For example, the devices for forming fluid droplets may have a circular or oval shape in the xy-plane and, according to such embodiments, the slots 2337 are configured are configured to host substantially cylindrical or oval cylindrical shaped objects.

[0240] In another example, according to some embodiments, the base / substrate of the fluid droplet forming device is a microscope slide or has similar xy plane dimensions to a microscope slide. Accordingly, in some embodiments, the slots 2337 herein have the same or similar dimensions in the xy plane to those of a microscope slide. Common dimensions of microscope slides in the xy plane include 46mm x 27mm, 48mm x 28mm, 75mm x 25mm, 76mm x 26mm, 75mm x 38mm, 76mm x 51mm, 76mm x 52mm, and the like. In some embodiments, the dimension of the slots 2337 in the xy plane is about 75mm x about 25mm, as 75mm x 25mm microscope slides are commonly available.

[0241] In some embodiments, the slots 2337 are configured such that a base / substrate layer of the article / device is able to securely rest on the holding tray 2330 and / or base 2310 during the centrifugation. For example, in some embodiments, when positioned within the slots 2337 of the aligner portion 2335, the article / device may rest securely on the bottom surface of the side portion 2331 or the base 2310. Alternatively, in some embodiments, as illustrated in FIG. 25, the aligner portion 2335 may include a bottom surface upon which the article / devices securely rests when positioned within he slots 2337 thereof.

[0242] In some embodiments, the aligner portion 2335 further comprises an alignment cutout 2339. In some embodiments, the alignment cutout 2339 comprises an opening in a flange or side section of the aligner portion 2335. The alignment cutout 2339 may be formed in any location suitable for aligning an article / device with a slot 2337. For example, in some embodiments, as illustrated in Figs. 25 and 26, a separate alignment cutout 2339 is formed relative to each slot 2337. Additionally or alternatively, in some embodiments, as illustrated in Fig. 25, an alignment cutout 2339 may span two or more slots 2337.

[0243] In some embodiments, one of the layers of the device herein comprises an element complementary with the alignment cutout 2339. For example, referring to Fig. 26, in some embodiments, the device includes an alignment lid 2500, the alignment lid 2500 including an alignment tab 2501. When a device comprising the alignment lid 2500 is inserted into a slot 2337 having an alignment cutout 2339, the alignment tab 2501 fits within the corresponding alignment cutout 2339 to align the device with the slot 2337. In some embodiments, a single alignment lid 2500 covers multiple devices / articles, such that positioning of the alignment tab 2501 within the alignment cutout 2339 aligns multiple devices / articles at the same time. Additionally or alternatively, multiple alignment tabs 2501 may fit within a single alignment cutout 2339, such that a single alignment cutout 2339 can align multiple devices / articles having separate alignment lids 2500 in individual slots 2337. Although described herein primarily with respect to an alignment tab 2501 extending from the device / article, and an alignment cutout 2339 formed in the aligner portion 2335, the disclosure is not so limited and may include an alignment tab formed on the aligner portion 2335 and a corresponding alignment cutout formed in the device / article.

[0244] When present, the optional holder lid 2350 is positioned on or over the holding tray 2330. In some embodiments, the dimensions of the upper surface of the holder lid 2350 is complementary with the lower surface of the holder base 2310 (or the bottom surface of the holding tray 2330 when the holder base 2310 is not present), such that multiple holders 2300 can be stacked on top of each other.

[0245] Kit

[0246] In some aspects, the present invention is directed to a kit for forming a fluid droplet.

[0247] In some embodiments, the kit comprises a droplet forming device and a holder for holding the droplet forming device during centrifugation.

[0248] In some embodiments, the droplet forming device is the same as or similar to the device described elsewhere herein. In some embodiments, the holder is the same as or similar to the holder described herein. Example

[0249] The instant specification further describes in detail by reference to the following experimental examples. These examples are provided for purposes of illustration only, and are not intended to be limiting unless so specified. Thus, the instant specification should in no way be construed as being limited to the following examples, but rather, should be construed to encompass any and all variations which become evident as a result of the teaching provided herein.

[0250] Referring to Figs. 27A-27K, glass microscope slides (Fisherbrand SuperFrost Plus™ 12- 550-15) were coated with 0.1% poly-L-lysine (Sigma, P8920) for 30 minutes at 37°C, then fully dried at 37°C for 30 minutes.

[0251] A droplet forming layer was created with 8 thermoplastic sample restraining modules in a 4x2 arrangement. The sample restraining modules were melted to the substrate (coated microscope slide) in two successive heat-cool cycles of 20 seconds at 200°C (SmartLine Hotplate Stirrer, MSH-800) and 20 seconds at room temperature on paper towels for heat dissipation. Gentle pressure was added by hand to the sample restraining modules after 10 seconds of each cooling cycle. This procedure was repeated to create 8 identical slides with 8 sample restraining modules each (Fig. 27 A, the item in the bottom).

[0252] Using a micropipette, fluid samples of human saliva cells suspended in PBS buffer (Invitrogen AM-9624) were added to each of the 8 sample restraining modules on each microscope slide, with one sample per module (Fig. 27B). Complete fluid droplet forming devices were created by combining the microscope slide / sample restraining module combo, a lid (3-D printed in-house, with holes to prevent vacuum sealing), and an adjustable clip (al70826WQ001, Guangzhou Openfind Electronic Commerce CO., LTD via Amazon) (Figs. 27C-27E). Specifically, the microscope slide / sample restraining module / lid combo containing saliva samples were placed inside the clip, and the screws were tightened with a screwdriver (Fig. 27D) to induce pressure, which prevents leakage of the saliva samples during centrifugation. The two screws of the adjustable clip were adjusted to ensure the evenly distribution of the pressure (Fig. 27E).

[0253] Eight complete units (i.e., the fully assembled fluid droplet forming devices containing the saliva samples) were placed in two holders, with 4 units per holder. Units were arranged in a pattern for centrifuge balancing due to the clip offset (Fig. 27F). Lids were added to protect samples from debris during centrifugation, to maintain sterile conditions, and provides the option to stack assemblies for high throughput (Fig. 27G).

[0254] The assemblies were single-stacked, and centrifuged at 1,600 RPM for 20 minutes in a swinging bucket centrifuge (Eppendorf 5430) with a wellplate rotor (Eppendorf A-2-MTP 022654403) (Fig. 27H).

[0255] After centrifugation, units were gently disassembled with a screwdriver. The fluid droplet forming layer (i.e., the sample restraining modules) were removed with forceps to reveal the array of fluid droplets. The droplets on the slides were allowed to fully dry at room temperature (Fig. 271). When dry, the slides were baked for 10 minutes at 60°C. Slides were rinsed by dipping them 3 times in a Coplin jar with distilled water, then fully dried at 60°C. Cells on the slides were fixed for 5 minutes by immersing slides in 100% methanol, then stained with Differential Stain (Newcomer Supply 9112). The procedure produced 8 replicas of saliva cells stained with Differential Stain (Fig. 27J). In practice, the 8 slides can be stained with different staining agents, or otherwise undergo different processes. Cells fixed on the slide were imaged (PhenoImager, 40X Brightfield) (Fig. 27K).

[0256] Enumerated Embodiments

[0257] In some aspects, the present invention is directed to the following non-limiting embodiments:

[0258] Embodiment 1: A holder, comprising: a holding tray having a plurality of slots for hosting one or more fluid droplet forming devices, wherein the holder holds one or more fluid droplet forming devices during centrifugation, and wherein, during the centrifugation, a downward centrifugal force is applied to the fluid droplet forming devices such that samples loaded in the fluid droplet forming devices move downwardly along the devices to form fluid droplets.

[0259] Embodiment 2: The holder of Embodiment 1, wherein the plurality of slots are configured to host fluid droplet forming devices having a substantially rectangular cuboid shape, a substantially cylindrical shape, or a substantially oval cylindrical shape. Embodiment 3: The holder of any one of Embodiments 1-2, which fits a centrifuge plate holder for holding microplates for centrifugation.

[0260] Embodiment 4: The holder of Embodiment 3, wherein exterior dimensions of the holder, or portions thereof, are substantially the same as those of a microplate, such that the holder fits a centrifuge plate holder.

[0261] Embodiment 5: The holder of Embodiment 4, wherein at least one of the following applies:

[0262] (a) bottom dimensions of the holder are substantially the same as those of a microplate;

[0263] (b) bottom outside flange dimensions of the holder are substantially the same as those of a microplate;

[0264] (c) lateral wall dimensions of the holder are substantially the same as those of a microplate; or

[0265] (d) height dimensions of the holder are substantially the same as those of a microplate.

[0266] Embodiment 6: The holder of any one of Embodiments 1-5, wherein the holding tray comprises at least two holding trays.

[0267] Embodiment 7: The holder of Embodiments 6, wherein: each of the holding trays comprises: a holder base under the holding tray; and a holder lid above the holding tray; an upper surface of the holder lid is configured to engage a lower surface of the holder base; and when the holding trays are stacked, adjacent holder bases and holder lids maintain a positioning of adjacent holding trays relative to each other, providing for stable vertical stacking.

[0268] Embodiment 8: The holder of any one of Embodiments 1-7, wherein the holding tray comprises an aligner having the plurality of slots, and a side tray.

[0269] Embodiment 9: The holder of any one of Embodiments 1-8, wherein one or more slots of the plurality of slots has an alignment cutout, such that a fluid droplet forming device having a complementary alignment tab can properly align with the slot when placed therein.

[0270] Embodiment 10: A kit, comprising: a fluid droplet forming device for forming an array of fluid droplet thereon, comprising: a substrate; and a droplet forming layer on the substrate, which has an upper opening and a lower opening in fluid communication with each other via a passage; and a holder for holding the device during centrifugation, wherein each slot of the plurality of slots holds one fluid droplet forming device, wherein the lower opening is in direct contact with the substrate, and wherein a fluid sample introduced into the upper opening of the droplet forming layer moves downwardly via the passage and settles on an upper surface of the substrate via the lower opening in response to a centrifugal force, and forms a fluid droplet on the substrate.

[0271] Embodiment 11 : The kit of Embodiment 10, wherein at least one of the following applies:

[0272] (a) the droplet forming layer is a first patterned template layer having a plurality of apertures for providing the upper opening, the lower opening, and the passage,

[0273] (b) the droplet forming layer is one or more sample restraining modules for providing the upper opening, the lower opening, and the passage.

[0274] Embodiment 12: The kit of any one of Embodiments 10-11, wherein the fluid droplet forming device comprises a holder alignment tab, wherein the one or more slots of the holding tray has an alignment cutout, and wherein the holder alignment cutout and the holder alignment tab align the fluid droplet forming device with the slot.

[0275] Embodiment 13: The kit of Embodiment 12, wherein the holder alignment tab is a part of the substrate, or a part of the droplet forming layer.

[0276] Embodiment 14: The kit of any one of Embodiments 12-13, wherein at least one of the following applies:

[0277] (a) the fluid droplet forming device further comprises a first patterned template layer, and the first patterned template layer comprises the holder alignment tab,

[0278] (b) the fluid droplet forming device further comprises a first patterned template layer and a second patterned template layer, and the second patterned template layer comprises the holder alignment tab, or

[0279] (c) the fluid droplet forming device further comprise a lid, and the lid comprises the holder alignment tab. Embodiment 15: The kit of any one of Embodiments 12-14, wherein the holder comprises a holding tray having a plurality of slots for hosting one or more fluid droplet forming devices, wherein the holder holds one or more fluid droplet forming devices and remains stably in a centrifuge during an application of the centrifugal force by the centrifuge.

[0280] Embodiment 16: The kit of Embodiment 15, wherein the holder fits a centrifuge plate holder for holding microplates for centrifugation.

[0281] Embodiment 17: The kit of any one of Embodiments 15-16, wherein exterior dimensions of the holder, or portions thereof, are substantially the same as those of a microplate, such that the holder fits a centrifuge plate holder.

[0282] Embodiment 18: The kit of any one of Embodiments 15-17, wherein at least one of the following applies:

[0283] (a) bottom dimensions of the holder are substantially the same as those of a microplate;

[0284] (b) bottom outside flange dimensions of the holder are substantially the same as those of a microplate;

[0285] (c) lateral wall dimensions of the holder are substantially the same as those of a microplate; or

[0286] (d) height dimensions of the holder are substantially the same as those of a microplate.

[0287] Embodiment 19: The kit of any one of Embodiments 15-18, further comprises a holder base under the holding tray, or a holder lid above the holing tray.

[0288] Embodiment 20: The kit of any one of Embodiment 19, which comprises the holder base and the holder lid, wherein a shape of an upper surface of the holder lid matches a shape of a lower surface of the holder base such that adjacent holder bases and holder lids lock into each other to allow multiple holders for stable vertical stacking.

[0289] Embodiment 21 : The kit of any one of Embodiments 15-20, wherein the holding tray comprises an aligner having the plurality of slots, and a side tray.

[0290] Embodiment 22: A method of forming a fluid droplet with the holder of any one of Embodiments 1-9, comprising: introducing a fluid sample into an upper opening of a droplet forming layer of the fluid droplet forming device; placing the fluid droplet forming device in a slot of the holder; placing the holder in a centrifuge plate carrier of a centrifuge; operating the centrifuge to apply a centrifugal force to the holder and the fluid droplet forming device held thereon, wherein the fluid sample moves downwardly via a passage in the droplet forming layer and settles on an upper surface of a substrate via a lower opening in response to the centrifugal force, thereby forming the fluid droplet on the substrate.

[0291] Embodiment 23: The method of Embodiment 22, further comprising removing the droplet forming layer from the substrate to make the fluid droplet formed on the substrate accessible for subsequent procedures.

[0292] Embodiment 24: The method of any one of Embodiments 22-23, further comprising forming a patterned array of fluid droplets on the substrate.

[0293] Embodiment 25: The method of Embodiment 24, wherein the fluid droplet forming device includes a plurality of passages, each of the plurality of passages forming a separate fluid droplet on the substrate, the separate fluid droplets forming the patterned array.

[0294] Embodiment 26: The method of any one of Embodiments 22-25, further comprising placing at least one additional fluid droplet forming device in another slot of the holder.

[0295] Embodiment 27: The method of Embodiment 26, wherein the operating of the centrifuge forms fluid droplets uniformly across the fluid droplet forming devices.

[0296] Embodiment 28: The method of any one of Embodiments 22-27, further comprising placing at least one additional holder in the centrifuge plate carrier of the centrifuge, each of the holder and the at least one additional holder containing one or more of the fluid droplet forming devices.

[0297] Identifiers Used in Drawings

[0298] Device: 100, 100’, 100”

[0299] Substrate: 110, 110”

[0300] Wick: 120, 120”

[0301] Opening(s) in wick: 122, 122”

[0302] First patterned template layer: 130, 130’, 130”, 200, 300, 400, 500, 550, 600, 700, 800, 900, 1200, 1300, 1400, 1400’, 1600, 1650, 2202, 2202’ Upper surface of first patterned template layer: 202, 302, 402, 602, 702, 802, 902, 1202, 1302, 1402, 1402’

[0303] Lower surface of first patterned template layer: 204, 304, 404, 904, 1304, 1404, 1404’

[0304] Apertures in first patterned template layer: 132, 132’, 206, 306, 406, 606, 706, 806, 906, 1206, 1306, 1406, 1406’, 2206’

[0305] Apertures in first patterned template layer at upper surface: 1306a, 1406a, 1406a’

[0306] Apertures in first patterned template layer at lower surface: 1306b, 1406b, 1406b’

[0307] Retaining protrusions above upper surface: 1412

[0308] Retaining protrusions below lower surface: 1414’

[0309] Window area in first patterned template layer: 134, 134”, 208, 308, 408, 608, 708, 808, 1208, 1308, 1408, 1408’, 2208, 2208’

[0310] Alignment feature(s) in first patterned template layer: 310a, 310b, 310c, 310d, 410a, 10b, 410c, 510a, 510b, 560a, 560b, 910

[0311] Filter: 140

[0312] Second patterned template layer: 150, 150”, 1000, 1100, 1700, 1750, 2202, 2202’

[0313] Upper surface of second patterned template layer: 1002, 1102

[0314] Lower surface of second patterned template layer: 1004, 1101

[0315] Window area in second patterned template layer: 154, 154”, 1008, 1108, 2208, 2208’

[0316] Apertures in second patterned template layer: 2206’

[0317] Alignment feature(s) in second patterned template layer: 1110

[0318] Lid: 160, 160”, 1900

[0319] Base of lid: 1902

[0320] Sidewall(s) of lid: 1904

[0321] Retaining feature(s) of lid: 1906

[0322] Funnel: 170’

[0323] Sample restraining module: 190, 190”, 195, 195”, 2212, 2212’

[0324] Upper opening of sample restraining module: 191

[0325] Lower opening of sample restraining module: 192

[0326] Internal passage of sample restraining module: 193

[0327] Upper portion of sample restraining module: 196

[0328] Lower portion of sample restraining module: 197 Filter of sample restraining module: 198

[0329] Holder: 2300

[0330] Holder base: 2310

[0331] Holding tray: 2330

[0332] Holding tray side tray: 2331

[0333] Holding tray aligner: 2335

[0334] Slot: 2337

[0335] Alignment cutout: 2339

[0336] Holder lid: 2350, 2500

[0337] Holder lid hole: 2503

[0338] Alignment tab: 2501 x???: Dimension of ??? in the x axis (e.g., X206 is the dimension of 206 in the x axis) y???: Dimension of ??? in the y axis (e.g., y206 is the dimension of 206 in the y axis) z???: Dimension of ??? in the z axis (e.g., Z200 is the dimension of 200 in the z axis) d???: Dimension of ??? in the xy plane (e.g., diameter or equivalent diameter) (e.g., deoe is the dimension of 606 in the xy plane) id???: Inner dimension of ??? in the xy plane (e.g., diameter or equivalent diameter) (e.g., id2208 is the inner dimension of 2208 in the xy plane)

[0339] Od???: Outer dimension of ??? in the xy plane (e.g., diameter or equivalent diameter) (e.g., od2208 is the outer dimension of 2208 in the xy plane)

[0340] The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

CLAIMSWhat is claimed is:

1. A holder, comprising: a holding tray having a plurality of slots for hosting one or more fluid droplet forming devices, wherein the holder holds one or more fluid droplet forming devices during centrifugation, and wherein, during the centrifugation, a downward centrifugal force is applied to the fluid droplet forming devices such that samples loaded in the fluid droplet forming devices move downwardly along the devices to form fluid droplets.

2. The holder of claim 1, wherein the plurality of slots are configured to host fluid droplet forming devices having a substantially rectangular cuboid shape, a substantially cylindrical shape, or a substantially oval cylindrical shape.

3. The holder of claim 1, which fits a centrifuge plate holder for holding microplates for centrifugation.

4. The holder of claim 3, wherein exterior dimensions of the holder, or portions thereof, are substantially the same as those of a microplate, such that the holder fits a centrifuge plate holder.

5. The holder of claim 4, wherein at least one of the following applies:(a) bottom dimensions of the holder are substantially the same as those of a microplate;(b) bottom outside flange dimensions of the holder are substantially the same as those of a microplate;(c) lateral wall dimensions of the holder are substantially the same as those of a microplate; or(d) height dimensions of the holder are substantially the same as those of a microplate.

6. The holder of claim 1, wherein the holding tray comprises at least two holding trays.

7. The holder of claim 6, wherein: each of the holding trays comprises: a holder base under the holding tray; and a holder lid above the holding tray; an upper surface of the holder lid is configured to engage a lower surface of the holder base; and when the holding trays are stacked, adjacent holder bases and holder lids maintain a positioning of adjacent holding trays relative to each other, providing for stable vertical stacking.

8. The holder of claim 1, wherein the holding tray comprises an aligner having the plurality of slots, and a side tray.

9. The holder of claim 1, wherein one or more slots of the plurality of slots has an alignment cutout, such that a fluid droplet forming device having a complementary alignment tab can properly align with the slot when placed therein.

10. A kit, comprising: a fluid droplet forming device for forming an array of fluid droplet thereon, comprising: a substrate; and a droplet forming layer on the substrate, which has an upper opening and a lower opening in fluid communication with each other via a passage; and a holder for holding the device during centrifugation, wherein each slot of the plurality of slots holds one fluid droplet forming device, wherein the lower opening is in direct contact with the substrate, and wherein a fluid sample introduced into the upper opening of the droplet forming layer moves downwardly via the passage and settles on an upper surface of the substrate via the lower opening in response to a centrifugal force, and forms a fluid droplet on the substrate.

11. The kit of claim 10, wherein at least one of the following applies:(a) the droplet forming layer is a first patterned template layer having a plurality of apertures for providing the upper opening, the lower opening, and the passage,(b) the droplet forming layer is one or more sample restraining modules for providing the upper opening, the lower opening, and the passage.

12. The kit of claim 10, wherein the fluid droplet forming device comprises a holder alignment tab, wherein the one or more slots of the holding tray has an alignment cutout, and wherein the holder alignment cutout and the holder alignment tab align the fluid droplet forming device with the slot.

13. The kit of claim 12, wherein the holder alignment tab is a part of the substrate, or a part of the droplet forming layer.

14. The kit of claim 12, wherein at least one of the following applies:(a) the fluid droplet forming device further comprises a first patterned template layer, and the first patterned template layer comprises the holder alignment tab,(b) the fluid droplet forming device further comprises a first patterned template layer and a second patterned template layer, and the second patterned template layer comprises the holder alignment tab, or(c) the fluid droplet forming device further comprise a lid, and the lid comprises the holder alignment tab.

15. The kit of claim 12, wherein the holder comprises a holding tray having a plurality of slots for hosting one or more fluid droplet forming devices, wherein the holder holds one or more fluid droplet forming devices and remains stably in a centrifuge during an application of the centrifugal force by the centrifuge.

16. The kit of claim 15, wherein the holder fits a centrifuge plate holder for holding microplates for centrifugation.

17. The kit of claim 15, wherein exterior dimensions of the holder, or portions thereof, are substantially the same as those of a microplate, such that the holder fits a centrifuge plate holder.

18. The kit of claim 15, wherein at least one of the following applies:(a) bottom dimensions of the holder are substantially the same as those of a microplate;(b) bottom outside flange dimensions of the holder are substantially the same as those of a microplate;(c) lateral wall dimensions of the holder are substantially the same as those of a microplate; or(d) height dimensions of the holder are substantially the same as those of a microplate.

19. The kit of claim 15, further comprises a holder base under the holding tray, or a holder lid above the holing tray.

20. The kit of claim 19, which comprises the holder base and the holder lid, wherein a shape of an upper surface of the holder lid matches a shape of a lower surface of the holder base such that adjacent holder bases and holder lids lock into each other to allow multiple holders for stable vertical stacking.

21. The kit of claim 15, wherein the holding tray comprises an aligner having the plurality of slots, and a side tray.

22. A method of forming a fluid droplet with the holder of claim 1, comprising: introducing a fluid sample into an upper opening of a droplet forming layer of the fluid droplet forming device; placing the fluid droplet forming device in a slot of the holder; placing the holder in a centrifuge plate carrier of a centrifuge; operating the centrifuge to apply a centrifugal force to the holder and the fluid droplet forming device held thereon,wherein the fluid sample moves downwardly via a passage in the droplet forming layer and settles on an upper surface of a substrate via a lower opening in response to the centrifugal force, thereby forming the fluid droplet on the substrate.

23. The method of claim 22, further comprising removing the droplet forming layer from the substrate to make the fluid droplet formed on the substrate accessible for subsequent procedures.

24. The method of claim 22, further comprising forming a patterned array of fluid droplets on the substrate.

25. The method of claim 24, wherein the fluid droplet forming device includes a plurality of passages, each of the plurality of passages forming a separate fluid droplet on the substrate, the separate fluid droplets forming the patterned array.

26. The method of any one of claims 22-25, further comprising placing at least one additional fluid droplet forming device in another slot of the holder.

27. The method of claim 26, wherein the operating of the centrifuge forms fluid droplets uniformly across the fluid droplet forming devices.

28. The method of claim 22, further comprising placing at least one additional holder in the centrifuge plate carrier of the centrifuge, each of the holder and the at least one additional holder containing one or more of the fluid droplet forming devices.

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