Reduced depth porous cell culture sample plate

Abstract

Disclosed is a porous plate for cell culture growth with reduced maximum depth. The perforated plate may also include a reduced skirt height.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority of U.S. Provisional Application No. 63 / 428,483, filed on November 23, 2022, pursuant to 35 U.S.C. § 119, the content of which is incorporated herein by reference in its entirety and for all purposes. Technical Field

[0003] The present disclosure relates to porous cell culture sample plates, and more particularly, to cell culture sample plates with reduced depth of sample wells. Background Art

[0004] It is known to culture cells in porous culture sample plates including a plurality of sample wells. Such porous plates are typically larger than necessary, such that the volume of each sample well is significantly greater than the volume of the aliquot to be placed therein. The corresponding height of the porous culture plate and its sample wells can impede the effective lateral movement of pipettes and other instruments accessing the sample wells. Additionally, the large volume of the sample wells increases the manufacturing cost due to the need for more raw materials than necessary. Summary of the Invention

[0005] In a first aspect, a porous plate is disclosed, comprising: a skirt including a bottom edge and an upper edge extending around a perimeter of the skirt; and a plurality of sample wells positioned within a boundary of the skirt, each sample well including a sidewall, a bottom wall, and a maximum depth defined between an upper edge of the sample well and an inner surface of the bottom wall. The sample wells are supported by a support structure attached to and extending between adjacent sidewalls of the sample wells and connecting at least one of the plurality of sample wells to the skirt. The distance between the upper edge of each sample well and a plane defined by the upper edge of the skirt can be equal to or less than about 5 mm, and the maximum depth of the sample well is less than about 1.8 cm.

[0006] In a second aspect, the maximum depth of each sample well of the first aspect can be equal to or less than about 1.5 cm;

[0007] In a third aspect, the maximum depth of each sample well of the first aspect can be equal to or less than about 1.2 cm;

[0008] In a fourth aspect, the maximum depth of each sample well of the first aspect can be in the range of about 1.0 cm to about 1.8 cm;

[0009] In a fifth aspect, the height defined between the bottom edge and the upper edge of the skirt of any one of the first aspect to the fourth aspect can be less than about 2 cm;

[0010] In a sixth aspect, the height of the skirt portion of the fifth aspect may be less than about 1.8 cm;

[0011] In a seventh aspect, at least a portion of each sample well of any one of the first through sixth aspects may extend above the support structure;

[0012] In an eighth aspect, the support structure of any one of the first through seventh aspects may include a plurality of webs; and

[0013] In a ninth aspect, the support structure of any one of the first through seventh aspects may include an upper support plate that surrounds and engages each sample well and further engages the skirt portion.

[0014] The foregoing general description and the following detailed description both present embodiments that are intended to provide an overview or framework for understanding the nature and characteristics of the embodiments disclosed herein. The drawings are included to provide a further understanding, and the drawings are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure and, together with the description, explain the principles and operations of the disclosure. Brief Description of the Drawings

[0015] Figure 1 is a top view of an exemplary multi-well plate and its lid including a plurality of sample wells arranged in a rectangular array and supported by a plurality of webs;

[0016] Figure 2 is Figure 1 a front cross-sectional view of the multi-well plate;

[0017] Figure 3 is Figure 2 a front cross-sectional view of the multi-well plate, wherein the bottom wall of each sample well is spaced apart from the lower plate;

[0018] Figure 4 is Figure 2 a front cross-sectional view of the multi-well plate, wherein the lower plate of the multi-well plate forms the bottom wall of the multi-well plate;

[0019] Figure 5 is a top view of an exemplary multi-well plate including a plurality of sample wells arranged in a rectangular array and supported by an upper plate that surrounds and engages the plurality of sample wells;

[0020] Figure 6 is Figure 5 a front cross-sectional view of the multi-well plate;

[0021] Figure 7 is a front cross-sectional view of another exemplary multi-well plate including a plurality of sample wells with a reduced maximum depth; and

[0022] Figure 8is an elevational cross-sectional view of another exemplary multiwell plate including a plurality of sample wells of reduced maximum depth and a skirt of reduced height. DETAILED DESCRIPTION

[0023] Reference will now be made in detail to embodiments of the present disclosure, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. However, the present disclosure may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0024] As used herein, the term "about" means that amounts, sizes, formulations, parameters and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller as necessary, reflecting tolerances, conversion factors, rounding, measurement errors, etc. and other factors known to those skilled in the art.

[0025] In this article, ranges can be expressed as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from one particular value to the other particular value. Similarly, when a value is expressed as an approximation by using the antecedent "about", it is understood that the particular value forms another embodiment. It should be further understood that the endpoints of each range are significant both relative to the other endpoint and independently of the other endpoint.

[0026] As used herein, directional terms, such as up, down, right, left, front, back, top, bottom, are made only with reference to the drawings drawn and are not intended to imply an absolute orientation.

[0027] Unless otherwise expressly stated, any method described herein is not intended to be construed as requiring that its steps be performed in a particular order, nor is it intended to require a particular orientation for any apparatus. Thus, if a method claim does not actually recite the order in which its steps are to be followed, or any apparatus claim does not actually recite the order or orientation of individual components, or if there is no other specific recitation in the claim or description that the steps are to be limited to a particular order, or if there is no recitation of a particular order or orientation of components of the apparatus, then no order or orientation is intended to be inferred in any respect. This applies to any possible non-explicit basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; ordinary meaning derived from grammatical organization or punctuation; and the number or type of embodiments described in the specification.

[0028] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a" or "an" component includes aspects having two or more such components unless the context clearly dictates otherwise.

[0029] The terms "exemplary", "example", or various forms thereof are used herein to mean serving as an instance, example, or illustration. Any aspect or design described herein as "exemplary" or "example" should not be construed as superior to or better than other aspects or designs. Additionally, examples are provided merely for clarity and understanding and are not intended to limit or restrict the disclosed subject matter or the relevant portions of the present disclosure in any way. It will be appreciated that a large number of additional or alternative examples with different ranges could be presented, but are omitted for brevity.

[0030] As used herein, unless otherwise specified, the terms "comprising" and "including" and their variants are to be construed as synonymous and open-ended. The list of elements following the transitional phrase "comprising" or "including" is a non-exclusive list, so elements other than those specifically recited in the list may also be present.

[0031] The terms "substantially", "essentially", and their variants as used herein are intended to mean that the described feature is equal to or approximately equal to a certain value or description. For example, a "substantially flat" surface is intended to mean a flat or approximately flat surface. Additionally, "substantially" is intended to mean that two values are equal or approximately equal. In some embodiments, "substantially" may mean values within about 10% of each other, e.g., within about 5% of each other, or within about 2% of each other.

[0032] Reference Figures 1-4 , an exemplary porous plate 10 is shown. The porous plate 10 (e.g., a microplate) includes a frame 12 and a plurality of open sample wells 14 received within the frame 12, each sample well 14 defining a volume 16 capable of receiving an aliquot of a sample to be assayed. The porous plate 10 may include a predefined number of sample wells arranged in rows and columns that are orthogonal to each other. For example, the porous plate 10 may include 12 sample wells, 24 sample wells, 48 sample wells, 96 sample wells, etc. However, the porous plate may have any number of sample wells 14 and is not limited to any particular number or configuration of sample wells. Each sample well 14 includes a sample well sidewall 18 and may also include a sample well bottom wall 20.

[0033] To prevent light transmission between adjacent sample wells 14, the sidewalls 18 may be formed of an opaque polymer material or filled with an inorganic TiO2 material. For assay techniques that require detecting very small amounts of light, such as in liquid scintillation counting, the staining used to render the frame 12 opaque may be light-colored (e.g., white) so as to be highly reflective and non-absorbing to ensure high counting efficiency relative to radioactive samples. White coloring is typically achieved with TiO2. However, the sidewalls 18 may be optically transparent. In some types of luminescence and fluorescence assays, the sidewalls 18 of the sample wells 14 are non-reflective and absorbing, in which case the sidewalls 18 may be formed of a blackened polymer. As is generally known and practiced, black coloring of a polymer can be achieved by adding a pigment material such as carbon black to the polymer blend at concentrations readily known and practiced in the art.

[0034] The bottom wall 20 of the sample well 14 may be formed of a transparent material. The transparent material may be, for example, a polymer material, an inorganic material (e.g., glass, such as borosilicate glass), pure silica, mica, or even a metal-coated film. The glass material may have high optical quality and flatness. When the multi-well plate 10 is used for microscopy to view samples and live cells within the sample wells 14, the optical flatness of the bottom wall 20 of the sample well 14 may be desirable. The bottom wall 20 of the sample well 14 may be formed of a glass sheet having a thickness similar to that of a microscope slide coverslip, which are manufactured to match the optics of a particular microscope lens. Although the bottom wall 20 may have any thickness, for microscopy, the bottom wall thickness 22 may be less than or equal to 500 microns, and the flatness may exhibit variations in the range of from about zero microns to about 10 microns across the diameter of the outermost bottom surface of an individual sample well 14. However, in additional embodiments, the bottom wall 20 may be curved, such as conical. One or more chemically active coatings (not shown) may be added to the upper surface 23 of the bottom wall 20.

[0035] In various aspects, the frame 12 may include a peripheral skirt 24 and a support structure that supports a plurality of sample wells 14. The skirt 24 further includes a top edge 26 and a bottom edge 28, wherein the height 30 of the skirt 24 is defined between the top edge 26 and the bottom edge 28. The support structure may include a plurality of webs 32 that extend between the sample well sidewalls 18. Additionally, a subset of the webs 32 may extend from the peripheral sample well sidewalls of the sample well array to an adjacent surface of the frame 12 (e.g., the skirt 24). Thus, each sample well 14 may be supported by a plurality of webs 32. The plurality of webs 32 together join each sample well sidewall 18 to the sample well sidewalls of adjacent sample wells and join the sample web sidewalls of the peripheral sample wells in the sample well array to the frame 12 (e.g., the skirt 24). The interconnectivity of the frame 12, the sample well sidewalls 18, and the webs 32 that join them provides rigidity to the multi-well plate 10 and to the individual sample wells 14 that include the multi-well plate.

[0036] The frame 12 may also include a bottom portion 34. The bottom portion 34 may be joined to the skirt portion 24 around the lower perimeter of the skirt portion 24 and the perimeter of the bottom portion 34, for example, by an adhesive or by plastic welding (heat sealing). Although the bottom portion 34 may be generally flat as a whole, it may have relief features formed on one of its surfaces, such as ridges, curves, lenses, raised portions, diffraction gratings, pits, concentric circles, recessed areas, and the like. Such features may be located on the bottom portion 34 such that the features shape or otherwise become features of the bottom wall 20 and may in turn enhance the performance of the assay, enhance or enable detection (as in the case of lenses and gratings), or be used to mechanically facilitate attachment to the frame 12 and / or the sample well 14. These relief features may be formed by any number of known methods, including vacuum thermoforming, pressing, chemical etching, laser machining, grinding, embossing, or precision rolling, depending on the material of the bottom portion 34.

[0037] In some embodiments, the skirt portion 24 may include a shoulder 36 configured to support a lid 38 for the multi-well plate 10 that includes a rim 40, the rim sized to fit over the upper portion of the multi-well plate 10 such that the bottom edge 42 of the rim 40 is supported on the shoulder 36. A top edge 26 extending around the perimeter of the skirt portion 24 may define a first plane 44. Each sample well 14 includes an upper edge 46 such that the resulting plurality of upper edges 46 define a second plane 48. The second plane 48 may be parallel to the first plane 44. Additionally, the second plane 48 may be spaced from the first plane 44 by a first distance 50. Further, each web 32 includes an upper web edge 52 such that the resulting plurality of upper web edges 52 define a third plane 54. The third plane 54 may be spaced from the second plane 48 by a second distance 56 and from the first plane 44 by a third distance 58, the third distance being the sum of the first distance 50 and the second distance 56. The third plane 54 may be parallel to the second plane 48.

[0038] In some embodiments, the bottom walls 20 of the plurality of sample wells may contact the bottom portion 34 of the frame 12 (see Figure 2 ). In other embodiments, the bottom walls 20 of the plurality of sample wells may be spaced from the bottom portion 34 of the frame 12 by a distance 60 (see Figure 3 ). In still other embodiments, the bottom portion 34 of the frame 12 forms the bottom of the sample well 14 such that the sample well sidewalls 18 are directly attached to the bottom portion 34 (see Figure 4), and the bottom portion 34 forms the bottom wall of each sample well. In such embodiments, the thickness 22 of the bottom wall 20 is the thickness of the bottom portion 34. Each sample well 14 includes a maximum internal depth 62 that extends between a second plane 48 (coincident with the upper edge 46) and the inner surface 23 of the bottom of the sample well. Each sample well also includes a maximum sidewall height 64 defined between the second plane 48 and the outer surface 66 of the bottom wall 20.

[0039] In still other embodiments, a support structure of an exemplary multi-well plate 100 is shown that includes an upper support plate 68 (see Figure 5 and 6 ) that replaces the web 32, wherein the upper plate 68 surrounds and engages each sample well 14 around the perimeter of the sample well (e.g., the sample well sidewall 18). The upper support plate 68 may further engage the frame 12 (e.g., the skirt 24) around the perimeter of the upper plate 68. The upper surface 70 of the upper support plate 68 may be recessed below the top edge 26 of the skirt 24. In an embodiment, the upper edge 46 of each sample well 14 that represents the mouth of the sample well opening is positioned below a first plane 44 defined by the top edge 26 of the skirt 24. As previously described, the upper edges 46 of the plurality of sample wells 14 define a second plane 48. The second plane 48 may be parallel to the first plane 44 and spaced apart from the first plane 44 by a first distance 50. The first distance 50 may be in the range of about 0.1 mm to about 5 mm, but other first distances 50 are contemplated.

[0040] The sample wells 14 can be of any volume and can be made in any cross-sectional shape, including but not limited to square sidewalls with flat or round bottoms, conical sidewalls with flat or round bottoms, and / or combinations thereof. The maximum depth 62 of the sample well at least partially determines the volume 16 of the sample well, which is typically significantly greater than the volume required for the cell culture medium to be added to the sample well. For example, the individual sample well volume of a typical 96-well microplate 10 can be about 300 microliters (μL) per sample well, while conventional cell culture operations may use up to about 100 μL per culture medium sample well. Similarly, the individual sample well volume of a 24-well microplate 10 can be about 3.5 milliliters (mL) per sample well, while conventional cell culture operations may use about 0.5 mL to about 1.0 mL per sample well. In other words, the typical culture medium height in the sample wells of a 24-well microplate can be about 0.25 centimeters (cm) to about 0.5 cm, while the sample well depth is typically about 2 cm. The sample well depth required to provide a sample well volume that is disproportionately large compared to the actual volume required for the culture medium can limit the operability of the pipettes and pipette tips of liquid handling devices (automatic or manual), especially in smaller sample well formats such as 24-sample well or 96-sample well microplates. In some cell culture procedures (e.g., clone picking, dome culture for organoid culture), this can add ergonomic stress to the technician operating the liquid handling device. Additionally, a maximum sample well depth 60 that is deeper than necessary means that the production of the microplate requires an unnecessary amount of polymer resin, thereby increasing the manufacturing cost.

[0041] Accordingly, a microplate design with a reduced sample well depth (e.g., sample well wall height) is disclosed, which can be more beneficial ergonomically than current microplates and can help manufacturers reduce costs by reducing raw material usage.

[0042] As Figure 7 shown, the microplate 200 is shown to be similar in design to the microplate 10, except that the maximum sample well depth 62 of each sample well 14 can be equal to or less than about 1.8 cm, such as equal to or less than about 1.5 cm, such as equal to or less than about 1.2 cm, or equal to or less than about 1.0 cm. Similarly, referring Figure 8 to Figure 7The porous plate 300 of the porous plate 100, except that the height 30 of the frame 12 (e.g., the skirt 24) of the porous plate 200 and the maximum depth 62 of the sample holes 14 can both be reduced, such that the height 30 of the skirt 24 can be less than about 2 cm. For example, in an embodiment, the first distance 50 between the first plane 44 and the second plane 48 can be less than about 5 mm, less than about 4 mm, less than about 3 mm, less than about 2 mm, less than about 1 mm. In some embodiments, the first distance 50 between the first plane 44 and the second plane 48 can be equal to zero, such that the height 30 of the skirt 24 can be equal to the maximum depth 62 of the sample holes 14. That is, the upper edge 46 of each sample hole 14 can be in the second plane 48 defined by the top edge 26 of the skirt 24. In an embodiment, the height 30 of the skirt 24 can be equal to or less than about 1.8 cm, such as equal to or less than about 1.5 cm, such as equal to or less than about 1.2 cm, or equal to or less than about 1.0 cm. Similarly, the maximum depth 62 of the sample holes 24 can be equal to or less than about 1.8 cm, such as equal to or less than about 1.5 cm, such as equal to or less than about 1.2 cm, or equal to or less than about 1.0 cm. In an embodiment, the thickness 72 of the sidewall 18 of the sample hole can be in the range of about 500 microns to about 2 mm, such as in the range of about 500 microns to about 1 mm. The reduced wall thickness can provide more surface area for cell cultures that can be placed in the sample holes. Additionally, the thinner sample hole walls can reduce the molding cycle time during manufacturing due to a better heat dissipation rate, and can improve dimensional tolerances due to reduced ejector pin deflection when forming the sample holes during injection molding.

[0043] Although Figure 7 and 8 the porous plate is shown as having an upper plate 68 that supports the sample holes 14, the porous plates 200 and 300 can include a web 32 that supports the sample holes 14. Additionally, Figure 2 、 3 or any of the bottom wall configurations shown in FIG. 4 can be applied to the porous plates 200 or 300.

[0044] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. Accordingly, it is intended that the present disclosure cover such modifications and variations provided that such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. A porous sample plate, comprising: A skirt portion, which includes a bottom edge and an upper edge extending around the perimeter of the skirt portion; A plurality of sample holes, which are positioned within the boundary of the skirt portion, and each sample hole includes a side wall, a bottom wall, and a maximum depth defined between the upper edge of the sample hole and the inner surface of the bottom wall; A support structure, which is attached to and extends between the side walls adjacent to the sample holes, and connects at least one of the plurality of sample holes to the skirt portion; And wherein the distance between the upper edge of each sample hole and the plane defined by the upper edge of the skirt portion is equal to or less than about 5 mm, and the maximum depth of each sample hole is less than about 1.8 cm.

2. The porous sample plate according to claim 1, wherein the maximum depth is equal to or less than about 1.5 cm.

3. The porous sample plate according to claim 1, wherein the maximum depth is equal to or less than about 1.2 cm.

4. The porous sample plate according to claim 1, wherein the maximum depth is in the range of about 1.0 cm to about 1.8 cm.

5. The porous sample plate according to any one of claims 1 to 4, wherein the height defined between the bottom edge and the upper edge of the skirt portion of the skirt portion is less than 2 cm.

6. The porous sample plate according to claim 5, wherein the height of the skirt portion is less than about 1.8 cm.

7. The porous sample plate according to any one of claims 1 to 6, wherein at least a portion of each sample hole extends above the support structure.

8. The porous sample plate according to any one of claims 1 to 7, wherein the support structure includes a plurality of webs.

9. The porous sample plate according to any one of claims 1 to 7, wherein the support structure includes an upper support plate, the upper support plate surrounds and engages each sample hole, and further engages the skirt portion.

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