WO2023154292A1 - Sample collection devices, test kits, systems and methods - Google Patents

Abstract

Sample collection devices, test kits, systems and methods are described herein. A sample collection device can comprise an absorbent material having a color changing zone that changes color in the presence of a liquid sample (e.g., tear sample). Another sample collection device comprises a galvanic sample collection device having a bulb that lights up when a sample from an absorbent material contacts electrodes or metal pastes coupled to the bulb. Another sample collection device comprises a loop configured to collect a liquid sample of a defined volume and retain it by surface tension forces. An assay cassette for receiving a sample collection device is provided herein having a compartment wherein a portion of a sample collection device is inserted into the compartment via a first slot, and a running buffer or other liquid can be added to the compartment via an opening separate from the first slot.

Description

SAMPLE COLLECTION DEVICES, TEST KITS, SYSTEMS AND METHODS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 63/307,987, filed February 8, 2022. This and all other extrinsic materials discussed herein, including publications, patent applications, and patents, are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of the term in the reference does not apply.

TECHNICAL FIELD

[0002] This disclosure relates to sample collection devices, test kits, systems and methods, including tear sample collection devices, test kits, systems and methods.

BACKGROUND

[0003] Tear fluid analysis contributes to a greater understanding of ocular and system diseases and disorders. Obtaining adequate samples for tear analysis can be challenging. Most tear sample collectors use specific capitally designs as tear sample collectors. Such collectors appear sharp and can be intimidating for patients and others whose tear sample are being collected. Further, such collectors can be rather difficult to use by untrained personnel, and are expensive to manufacture.

[0004] The Quidel InflammaDry™ test uses a wick type tear sample collector. Unfortunately, it can be difficult to identify if a suitable sample has been collected. Other tear sample collectors employ a Q-tip design or filter paper strips (Shrimer’s test), and are imprecise and difficult to produce.

SUMMARY

[0005] Various tear sample collection devices (also referred to herein as sample collectors), test kits, systems and methods are described herein. Contemplated devices, test kits, systems can advantageously be cost-effective to produce on a mass scale, be easy to use, and have a soft and non-intimidating appeal to the person collecting a tear sample, and the person from whom a tear sample is collected. [0006] In an aspect of the disclosure, a sample collector (e.g., a tear sample collection device) is provided, comprising a first component having an indicator zone and a collection zone, wherein the indicator zone is configured to visibly change color when a sample (e.g., a tear sample) collected via the collection zone reaches the indicator zone. In some embodiments, the indicator zone comprises at least one of a color changing dye band and embedded fibers of a first color, wherein the first color is different from a second color of the first component. In some embodiments, the color changing dye changes color based on a pH of a sample contacting the dye. In some embodiments, the first component comprises an absorbent piece of material. In some embodiments, the indicator zone comprises an absorbent piece of material and the collection zone comprises a mesh material different from the absorbent piece of material. In some embodiments, the mesh material is configured to hold a sample (e.g., a liquid sample) by capillary action. In some embodiments, the first component comprises an absorbent material (e.g., a cellulose membrane, tissue-based material impregnated with absorbent polymers, paper, filter paper, polytetrafluoroethylene (PRFE)) along a full length of the first component extending across the indicator and collection zones. In some embodiments, the sample collector further comprises a second component having upper and lower pieces of material, wherein the first component is at least partially sandwiched between the upper and lower pieces of material of the second component. In some embodiments, the second component is configured to prevent a dye of the indicator zone from contacting an eye of a subject during sample collection.

[0007] In an aspect of the disclosure, a laminated sample collector is provided, comprising a first piece of material, a second piece of material, and an absorbent material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent material comprises a color changing zone. In some embodiments, the color changing zone comprises a color changing dye. In some embodiments, the color changing zone comprises embedded fibers of a first color, wherein the first color is different from a second color of the absorbent material. In some embodiments, the color changing dye comprises a sulfonephthalein. In some embodiments, the color changing dye comprises a Bromocresol green dye. In some embodiments, the color changing dye is configured to change in color when a target sample contacts the dye, and wherein the target sample comprises a tear sample. In some embodiments, a sandwiched portion of the absorbent piece of material comprises the at least one of the color changing dye band and the embedded fibers of the first color, and wherein each of the first and second pieces of material is transparent or semi-transparent (e.g., a clear plastic). [0008] In an aspect of the disclosure, a laminated card is provided comprising a first piece of material, a second piece of material, and an absorbent piece of material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent piece of material comprises a color changing zone comprising at least one of a color changing dye and embedded fibers of a first color, wherein the first color is different from a second color of the absorbent material, and wherein the laminated card is sized and dimensioned to form a plurality of laminated sample collectors. In some embodiments, the laminated card is scored. In some embodiments, the laminated card has thinned portions including a first thinned portion, and wherein the first thinned portion separates a first laminated sample collector of the plurality of laminated sample collectors from a second laminated sample collector of the plurality of laminated sample collectors. In some embodiments, the color changing dye comprises a sulfonephthalein. In some embodiments, the color changing dye comprises a Bromocresol green dye. In some embodiments, the color changing dye is configured to change in color when a target sample contacts the dye, and wherein the target sample comprises a tear sample. In some embodiments, a sandwiched portion of the absorbent piece of material comprises the at least one of the color changing dye band and the embedded fibers of the first color, and wherein each of the first and second pieces of material is transparent.

[0009] In an aspect of the disclosure, a sample collector is provided comprising upper and lower transparent pieces of material, and an absorbent piece of material coupled to at least one of the upper and lower transparent pieces of material, wherein a portion of the absorbent piece of material comprises a color changing zone. In some embodiments, the color changing zone comprises at least one of a color changing dye and embedded fibers of a first color. In some embodiments, the portion of the absorbent piece of material where the fibers of the first color are embedded is a second (e.g., lighter, translucent) color different from the first color. In some embodiments, the sample collector further comprises a stopper sized and dimensioned to prevent insertion of the sample collector into a cassette slot beyond a predetermined length. In some embodiments, the stopper is formed by the upper and lower transparent pieces of material having a greater width than at least a portion of the absorbent piece of material.

[0010] In an aspect of the disclosure, a sample collector is provided, comprising a handle, a flexible connector, and a loop, wherein the flexible connector couples the handle to the loop. In some embodiments, the loop is sized and dimensioned to collect a liquid sample of a defined volume and retain it by surface tension forces. In some embodiments, the loop is circular, oval, or polygonal. In some embodiments, the loop has a diameter or central length of l-10mm. In some embodiments, the loop comprises an empty center. In some embodiments, a mesh material is positioned within the loop. In some embodiments, a porous material is positioned within the loop.

[0011] In an aspect of the disclosure, a sample collector is provided comprising a loop configured to collect a liquid sample and at least temporarily retain it by surface tension forces.

[0012] In an aspect of the disclosure, a sample collector is provided comprising upper and lower pieces of material, and an absorbent piece of material coupled to at least one of the upper and lower pieces of material, wherein the at least one of the upper and lower pieces of material comprises a first electrode printed or otherwise positioned thereon, and a second electrode printed or otherwise positioned thereon, wherein the first electrode is made from a first metal, and wherein the second electrode is made from a second metal different from the first metal. In some embodiments, the sample collector comprises a first light coupled to the first and second electrodes. In some embodiments, the first light (a light housed in a bulb) comprises a low power LED light. In some embodiments, when a sufficient amount of a sample (e.g., an amount of a tear sample) is present on the absorbent piece of material, the sample reaches the first and second electrodes causing a small current to be created to cause the first light to light up. In some embodiments, the first metal comprises zinc and the second metal comprises copper.

[0013] In an aspect of the disclosure, a sample collector is provided, comprising an indicator zone comprising a color changing dye, wherein the color changing dye is configured to change color in the presence of a target sample. In some embodiments, the dye comprises a Bromocresol green dye. In some embodiments, the indicator zone comprises a fill line indicator zone. In some embodiments, the collector is an absorbent piece of material. In some embodiments, the collector comprises a strip. In some embodiments, the collector comprises a sample collection space between first and second pieces. In some embodiments, at least a portion of the collector is sized and dimensioned for inserting in a sample receiving port of an assay. In some embodiments, the sample collector further comprises a strip having the indicator zone comprising the color changing dye, wherein the strip further comprises a collection zone upstream of the indicator zone. In some embodiments, the sample collector further comprises a handle portion, wherein the indicator zone is between the handle portion and the collection zone.

[0014] In an aspect of the disclosure, an assay cassette for receiving a sample collector is provided, comprising an upper surface having a first opening to a first compartment, and a side surface having a second opening to the first compartment, wherein the second opening is sized and dimensioned to allow a first portion of the sample collector holding a sample (e.g., tear sample) to be placed in the first compartment. In some embodiments, the first opening is sized and dimensioned to allow a running buffer to be added into the first compartment directly onto the first portion of the tear collector. In some embodiments, when the first portion of the sample collector is positioned in the first compartment, a second portion of the sample collector is positioned outside of the first compartment. In some embodiments, the upper surface further comprises a window providing visibility to a test strip in the assay cassette. In some embodiments, the sample collector comprises any of the sample collectors described in this application.

[0015] Other advantages and benefits of the disclosed proteins, and related assays, test kits and methods will be apparent to one of ordinary skill with a review of the following drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The details of embodiments of the present disclosure, both as to their structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which:

[0017] Fig. 1 are images showing various color changing pH dyes on a cellulose membrane before and after addition of artificial tear;

[0018] Fig. 2 illustrates a color change to an edge sprayed with Bromocresol 0.1% Green from Isopropanol solution;

[0019] Fig. 3 illustrates geometry dependent absorbent capacity of a Porex™ membrane of 3x3 mm with red color dye solution applied at different volumes;

[0020] Fig. 4 illustrates a membrane fill capacity by length;

[0021] Fig. 5 illustrates a set of laminated tear samplers, according to an embodiment;

[0022] Fig. 6 illustrates a laminated dye-infused card, according to an embodiment;

[0023] Fig. 7 illustrates a sample collector strip cut from the laminated card of Fig. 6 before and after applying a sample to the strip, according to an embodiment; [0024] Fig. 8 illustrates a sample being picked up by a strip of Fig. 7, according to an embodiment;

[0025] Fig. 9 illustrates a first use case scenario including a cassette, sample collector in a diluent tube, a sample transfer pipette, and a reader;

[0026] Fig. 10 illustrates a second use case scenario with a sample collector strip inserted into a sample port of a cassette;

[0027] Fig. 11 illustrates a third use case scenario with a tear sample strip inserted into a cassette of the disclosure having a slot specifically for the strip;

[0028] Fig. 12 illustrates a cassette with sample slots, according to an embodiment;

[0029] Fig. 13 A illustrates a sample collector, according to an embodiment;

[0030] Fig. 13B illustrates another sample collector, according to another embodiment;

[0031] Fig. 13C illustrates another sample collector, according to another embodiment;

[0032] Fig. 13D illustrates another sample collector, according to another embodiment;

[0033] Fig. 13E illustrates another sample collector, according to another embodiment;

[0034] Fig. 13F illustrates a laminated card, according to an embodiment;

[0035] Fig. 14 illustrates a galvanic tear detector, according to an embodiment;

[0036] Fig. 15A illustrates a tear sample collector having a collection loop, according to an embodiment;

[0037] Fig. 15B illustrates another tear sample collector having a collection loop, according to another embodiment;

[0038] Fig. 15C illustrates another tear sample collector having a collection loop, according to another embodiment;

[0039] Fig. 16A illustrates a method of collecting and transferring a sample, according to an embodiment; [0040] Fig. 16B illustrates another method of collecting and transferring a sample, according to another embodiment;

[0041] Fig. 17A illustrates a sample collector having an empty loop, according to an embodiment;

[0042] Fig. 17B illustrates a sample collector having a mesh loop, according to an embodiment; and

[0043] Fig. 17C illustrates a sample collector having a porous loop, according to an embodiment.

DETAILED DESCRIPTION

[0044] The detailed description set forth below, in connection with the accompanying drawings, is intended as a description of various embodiments, and is not intended to represent the only embodiments in which the disclosure may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that embodiments of the invention can be practiced without these specific details. In some instances, well-known structures and components are shown in simplified form for brevity of description.

[0045] Various sample collection devices, test kits, systems and methods are provided herein.

[0046] In an aspect of the disclosure, a sample collector (e.g., a tear sample collection device) is provided, comprising a first component having an indicator zone and a collection zone, wherein the indicator zone is configured to visibly change color when a sample (e.g., a tear sample) collected via the collection zone reaches the indicator zone. In some embodiments, the indicator zone comprises at least one of a color changing dye band and embedded fibers of a first color, wherein the first color is different from a second color of the first component. In some embodiments, the color changing dye changes color based on a pH of a sample contacting the dye. In some embodiments, the first component comprises an absorbent piece of material.

[0047] Such sample collectors are advantageously cost-effective to produce on mass scale, easy to use, and soft and non-intimidating to both the person collecting the sample, and the subject whose sample is being collected. [0048] It is contemplated that any suitable color changing dye can be provided on an indicator zone (whether now known or later discovered), depending on the sample to be collected. Several color changing pH indication dyes are known, including for example, Bromothymol blue, Bromocresol green, Phenol red, Methyl red, universal indicator, and phenolphthalein. Without wishing to be bound by any particular theory, it is contemplated that the color change of a dye over a range of pH values is caused by the dissociation of the H+ ion from the indicator itself. Color changing pH dyes are generally specific to a range of pH values. Universal indicator dyes are used for a broader pH range with a larger number of color changes. In some contemplated embodiments, the color changing dye is placed on an absorbent paper or other absorbent material, which can be acidic (pH<7) in nature. The addition of a tear or other biofluid to such a material can change the pH to be >7, causing a color shift. Bromocresol green is a light yellow below a pH of about 3.8, but changes rapidly to blue at a pH>5.4. Human biofluids typically have a pH of between about 6.5 to about 7.6, or between about 7.2 to about 7.4. The transition using bromocresol green is striking, making it an ideal indicator. Some other dyes that change color but have a less striking color change include p-Nitrophenol (colorless to yellow). Some other examples of color changing dyes include, among others, Dichlorofluorescein (colorless to green), Bromothymol Blue (yellow to green), Phenol Red (yellow to red), or any other color changing dye that has a color shift from acidic (pH<7) to basic (pH>7). As used herein, a color changing dye can include some natural pigments such as those derived from Red Cabbage, Red Onion, Beets that display color shift behavior. In some embodiments described herein, a color change in a color changing pH dye can be detectable between about pH 3 to about pH 8, between about pH 4 to about pH 6, between about pH 3 to about pH 7, or between about pH 5 to about pH 6.

[0049] Now turning to Figure 1, an illustration of images taken when screening color changing pH dyes on a cellulose membrane is provided. The upper image 10 illustrates 2pL of a dye (Bromothymol blue 100, Bromocresol green 110, Phenol red 120, and Methyl red 130) in isopropyl alcohol (iPrOH) on a cellulose membrane. The lower image 20 illustrates the cellulose membrane with dye of the upper image with 2pL artificial tear added thereto. As shown in the two illustrations in the left column, bromothymol blue dye turned from light red color to an orange color. As shown in the two illustrations to the right of the bromothymol blue dye illustrations, bromocresol green dye changed from a yellow to blue where the artificial tear was applied (and maintained a yellow ring around the blue). As shown in the two illustrations to the right of the bromocresol green dye illustrations, phenol red changed from having a red center surrounded by clear, to having a red center surrounded by a yellow/orange color when the artificial tear was applied. As shown in the two illustrations of the far right column, methyl red changed from having an orange color to having a slightly darker orange/red color when the artificial tear was applied.

[0050] Additionally or alternatively to a color changing dye, in some embodiments the indicator zone can comprise embedded fibers of a first color, wherein the first color is different from a second color of the first component. For example, for a transparent, white, off-white or other absorbent material, blue, red, orange, purple, green, or other colored fibers can be at least partially embedded therein. When a sample is present on the indicator zone, the colored fibers will be more vibrant or darker, making them more visible and providing a visual indication that a target sample is in contact with the indicator zone.

[0051] Now turning to Figure 2, a tear sample collector fill-up indicator is illustrated. 200A illustrates an absorbent material edge sprayed with Bromocresol Green 0.1% solution in Isopropanol. 200B illustrates a diluted tear sample being applied to a portion of the absorbent material without the color changing dye. Figure 200C illustrates an observable color change (from a soft yellow to vibrant blue) when the tear sample reaches the dye band.

[0052] Figure 3 is an illustration of images taken of Porex™ membrane cut into 3mm x 3mm pieces. Red color dye solution was applied at different volumes (2pL at 310, 3pL at 320, 4pL at 330, 5pL at 340), to the 3mm x 3mm pieces. In the experiment illustrated, the capacity of a 3mm x 3mm piece of Porex membrane # 36776 was determined to be 4pL. With 5pL, the dye spread onto the surface beneath the Porex membrane.

[0053] Figure 4 is an illustration of images taken of 2mm strips cut from a Porex membrane # 36776. Sequential addition of pL red color dye solution was added and the fill-up length was measured by a ruler. At 400A, the strip has no red dye solution. At 400B, 2pL of red dye solution was added and the fill-up length was measured to be about 3mm. At 400C, an additional 2pL of red dye solution was added (for a total of 4pL), and the fill-up length was measured to be about 6mm showing the response is linear up to 4pL. For a 2pL tear sampler, a 2mm x 3mm cutout for membrane #36776 was found to be suitable. However, it should be appreciated that various cutouts from various membranes of different sizes are contemplated to also be suitable, for example, depending on the material(s) used. [0054] In an aspect of the disclosure, a laminated sample collector is provided, comprising a first piece of material, a second piece of material, and an absorbent material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent material comprises a color changing zone. In some embodiments, the color changing zone comprises a color changing dye. In some embodiments, the color changing zone comprises embedded fibers of a first color, wherein the first color is different from a second color of the absorbent material. In some embodiments, the color changing dye comprises a sulfonephthalein. In some embodiments, the color changing dye comprises a Bromocresol green dye. In some embodiments, the color changing dye is configured to change in color when a target sample contacts the dye, and wherein the target sample comprises a tear sample. In some embodiments, a sandwiched portion of the absorbent piece of material comprises the at least one of the color changing dye band and the embedded fibers of the first color, and wherein each of the first and second pieces of material is transparent or semi-transparent such that the color change can be visible through a piece of the transparent material.

[0055] In an aspect of the disclosure, a laminated card is provided comprising a first piece of material, a second piece of material, and an absorbent piece of material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent piece of material comprises a color changing zone comprising at least one of a color changing dye and embedded fibers of a first color, wherein the first color is different from a second color of the absorbent material, and wherein the laminated card is sized and dimensioned to form a plurality of laminated sample collectors. In some embodiments, the laminated card is scored. In some embodiments, the laminated card has thinned portions including a first thinned portion, and wherein the first thinned portion separates a first laminated sample collector of the plurality of laminated sample collectors from a second laminated sample collector of the plurality of laminated sample collectors. In some embodiments, the color changing dye comprises a sulfonephthalein. In some embodiments, the color changing dye comprises a Bromocresol green dye. In some embodiments, the color changing dye is configured to change in color when a target sample contacts the dye, and wherein the target sample comprises a tear sample. In some embodiments, a sandwiched portion of the absorbent piece of material comprises the at least one of the color changing dye band (or a portion thereof) and the embedded fibers of the first color, and wherein each of the first and second pieces of material is transparent.

[0056] Now turning to Figure 5, a laminated sample collector 560 is illustrated, which is formed from a card 500 comprising an upper transparent sheet 520, a lower transparent sheet 510, an absorbent material 530 having a band 540 at least partially sandwiched between upper transparent sheet 520 and lower transparent sheet 510. The band 540 is a color changing zone comprising at least one of a color changing dye and embedded color fibers that become more strongly visible when wetted. Card 500 can be separated into a plurality of laminated sample collectors, for example, via a die-cut or other cutting process, by separating at score lines, or any other suitable mechanism. In some embodiments, card 500 can comprise scoring (e.g., channel line or recessed depth) or perforations to make separation of the sample collectors easier. In some embodiments, card 500 can comprise a set of lines that indicate where card 500 should be cut to form the individual sample collectors (e.g., between 5-50 or between 10-25 sample collectors). In some embodiments, it is contemplated that sample collectors of the same size or different sizes can be formed from a single card.

[0057] Figure 6 illustrates a laminated dye-infused card 600, according to another embodiment. Lamination 610 can be clear or transparent, such that a change in color in dye band 620 is visible through lamination 610. Absorbent material 630 comprises a dye band portion 620, which is secured in lamination 610 such that a portion of absorbent material 630 not including chemical dye contacts the subject’s eye while a tear sample is being collected but the dye does not. Figure 7 illustrates images of a sample collector formed from card 600 before and after a tear sample is applied to the absorbent material. Prior to sample fill-up, the dye band is a first color. After sample fill-up, the dye band is a second color different from the first color. In some embodiments, the first color is yellow and the second color is blue. In some embodiments, the first color is red and the second color is orange. However, all suitable first and second colors, and all suitable color changing dyes are contemplated herein.

[0058] In an aspect of the disclosure, a sample collector is provided, comprising an indicator zone comprising a color changing dye, wherein the color changing dye is configured to change color in the presence of a target sample. In some embodiments, the dye comprises a Bromocresol green dye. In some embodiments, the indicator zone comprises a fill line indicator zone. In some embodiments, the collector is an absorbent piece of material. In some embodiments, the collector comprises a strip (for example, including the absorbent piece of material). In some embodiments, the collector comprises a sample collection space between first and second pieces. In some embodiments, at least a portion of the collector is sized and dimensioned for inserting in a sample receiving port of an assay. In some embodiments, the sample collector further comprises a strip having the indicator zone comprising the color changing dye, wherein the strip further comprises a collection zone upstream of the indicator zone. In some embodiments, the sample collector further comprises a handle portion, wherein the indicator zone is between the handle portion and the collection zone.

[0059] In an aspect of the disclosure, an assay cassette for receiving a sample collector is provided, comprising an upper surface having a first opening to a first compartment, and a side surface having a second opening to the first compartment, wherein the second opening is sized and dimensioned to allow a first portion of the sample collector holding a sample (e.g., tear sample) to be placed in the first compartment. In some embodiments, the first opening is sized and dimensioned to allow a running buffer to be added into the first compartment directly onto the first portion of the tear collector. In some embodiments, when the first portion of the sample collector is positioned in the first compartment, a second portion of the sample collector is positioned outside of the first compartment. In some embodiments, the upper surface further comprises a window providing visibility to a test strip in the assay cassette. In some embodiments, the sample collector comprises any of the sample collectors described in this application.

[0060] Figure 8 illustrates a sample 810 (e.g., a tear sample) being collected by a sample collector comprising a dye band of a first color 820 (illustrated in 800A), which changes to a second color 830 (illustrated in 800B) different from first color 820 once sample 810 contacts the dye band. Figure 9 illustrates a system for use of the sample collector including the tear sample in connection with a test cassette. The system comprises a test cassette 910, a sample collector with tear sample 915 in a diluent tube 920, a sample transfer pipette 930, and a reader 940. In the example shown, the tear sample collector with tear sample is inserted into the diluent tube. The sample is dislodged by tube inversion. The sample is added to the cassette from the diluent tube using the sample transfer pipette. The cassette is then placed into a reader and read after a period of time (e.g., after 15 minutes). The reader can comprise any suitable reader, for example, a lateral flow reader for one or more of visual, qualitative, and quantitative assays. Figure 10 illustrates a cassette 1010 for a sample collector 1020. A sample collector of the disclosure (e.g., sample collector 1020) can be used with an existing cassette. In the example shown, a portion of the sample collector comprising a sample is inserted directly into a sample port of the cassette. Running buffer (e.g., 2-3 drops) is added on top of the sample collector to draw the sample onto the test membrane. The cassette is then placed into a reader and read after a period of time. Figures 11-12 illustrate a cassette 1200 of the disclosure, according to an embodiment, used with a sample collector. Cassette 1200 comprises slots 1210 and 1220 on a first side surface of cassette 1200. Slot 1220 is sized and dimensioned to allow a first portion of the sample collector holding a sample (e.g., tear sample) to be placed in a first compartment. Slot 1210 is optionally sized and dimensioned to allow a first portion of a sample collector holding a sample to be placed in a second compartment. In some embodiments, a first opening (e.g., sample port) is provided on an upper surface of cassette 1200. In some embodiment, the upper surface is perpendicular or about perpendicular to the first side surface. The first opening is sized and dimensioned to allow a running buffer to be added into the first compartment directly onto the first portion of the sample collector in the first compartment. A second opening can be provided on the upper surface to allow a running buffer to be added into the second compartment directly onto the first portion of a sample collector in the second compartment. An upper surface of cassette 1200 can further comprise one or more windows providing visibility to one or more test strips in the assay cassette, as shown in Figures 11 and 12. As shown at 1110, a sample collector is inserted into cassette slot 1220. As shown at 1120, running buffer is added via the first opening on the upper surface of cassette 1200.

[0061] In an aspect of the disclosure, a sample collector is provided comprising upper and lower transparent pieces of material, and an absorbent piece of material coupled to at least one of the upper and lower transparent pieces of material, wherein a portion of the absorbent piece of material comprises a color changing zone. In some embodiments, the color changing zone comprises at least one of a color changing dye and embedded fibers of a first color. In some embodiments, the portion of the absorbent piece of material where the fibers of the first color are embedded is a second (e.g., lighter, translucent) color different from the first color. In some embodiments, the sample collector further comprises a stopper sized and dimensioned to prevent insertion of the sample collector into a cassette slot beyond a predetermined length. In some embodiments, the stopper is formed by the upper and lower transparent pieces of material having a greater width than at least a portion of the absorbent piece of material.

[0062] Figures 13A-13F illustrate some exemplary sample collectors of the disclosure. Figure 13A illustrates a sample collector having a length of about 30-40mm, a handle portion having a length of about 26-27mm, a color changing zone or band having a length of less than 1mm, and an absorbent material portion for collecting a sample (e.g., directly from a subject’s eye) having a length of about 3mm. A width of the sample collector is about 2mm. In the embodiment shown, a sample collected at absorbent material portion would travel to the color changing zone. The color changing zone can provide an indication that the right sample is collected. The color changing zone can provide an indication that a suitable amount is collected with a change in color. In some aspects, the color changing zone can change from a first color to a second, different color when a first type of sample is collected. In some aspects, the color changing zone can change from a first color to a third color different from the first and second colors when a second type of sample is collected. In some aspects, the color changing zone can remain the first color when a third type of sample is collected. While the sample collector of Figure 13 A is illustrated with specific dimensions, it should be appreciated that the sample collectors of the disclosure can be of any suitable size, shape and dimensions, and be made of any suitable material (e.g., plastic, paper or other handle portion, absorbent material, mesh material, porous material for sample contacting portion, absorbent material for color changing zone). For example, a length of a sample collector can be, for example, between lcm-20cm, between 3-4cm, between 2-5cm, between l-8cm, or any other suitable length; a length of a handle portion can be, for example, between 50-99%, between 75-99%, between 80-99%, between 85-95% of a length of the sample collector, or any other suitable length; a length of a color changing zone can be, for example, between 0.1-5mm, between 0.1-2mm, between 0.3- 1.5mm, or any other suitable length; and a length of the absorbent material leading up to the color changing zone can be, for example, between l-10mm, between l-5mm, between 2-4mm, or any other suitable length. A width of the absorbent material leading up to the color changing zone can be, for example, between l-5mm between l-3mm, between 1.5-2.5mm, or any other suitable width. Where provided, a stopper can have a width that is, for example, between 2- 10mm between 2-5mm, or any other suitable width. In some aspects, a stopper can have a width that is at least 110%, at least 120%, at least 130%, or at least 150% of a width of the absorbent material leading up to the color changing zone. In some aspects, the color changing zone can be sandwiched within handle portion (e.g., where handle portion is clear or transparent).

[0063] Figure 13B illustrates another sample collector having a widened handle portion forming a stopper that blocks sample collector from being inserted into a test cassette beyond the stopper (portion of handle widened closest to absorbent material. Figure 13C illustrates another sample collector having a widened handle portion forming a stopper. Rather than having a curved stopped as shown in Figure 13B, the stopper of Figure 13C forms sharp 90 degree angles. Figure 13D illustrates another sample collector of the disclosure, which comprises a larger end portion (e.g., an oval), which can advantageously make it easier for a user to hold while collecting and processing a sample. Figure 13E illustrates another sample collector comprising a larger end portion, here extending towards a first side while a second side aligns with the rest of the handle portion. Such a sample collector can make it easier for a user to, for example, insert the sample collector into a test cassette slot, or hold while collecting a sample. Figure 13F illustrates a set of scored sample collectors, which can be separated and used. In some embodiments, a sleeve or cover can be provided around a portion of the sample collector that is used to collect a sample (e.g., by contacting a person’s eye).

[0064] In an aspect of the disclosure, illustrated in Figure 14, a sample collector 1400 for galvanic tear detection is provided comprising a first piece of material, and an absorbent piece of material coupled to the first piece of material. In some embodiments, a second piece of material is provided and the first and second pieces sandwich at least a portion of the absorbent material. In some embodiments, the first and second pieces comprise first and second plastic sheets. The first piece of material comprises a first electrode 1410 printed or otherwise positioned thereon (e.g., on an inner surface such that it is covered by the first and second pieces), and a second electrode 1420 printed or otherwise positioned thereon (e.g., on an inner surface such that it is covered by the first and second pieces), wherein the first electrode is made from a first metal, and wherein the second electrode is made from a second metal different from the first metal. In some embodiments, the sample collector comprises a light 1430 coupled to the first and second electrodes. In some embodiments, the light comprises a low power LED light. While a low power LED light is shown in this example, any suitable light(s) are contemplated. In some embodiments, when a sufficient amount of a sample (e.g., an amount of a tear sample) is present on the absorbent piece of material, for example, when the sample reaches the first and second electrodes, a small current is created which lights up the low power LED (or other light(s) connected to the electrodes). In some embodiments, the first metal comprises zinc and the second metal comprises copper. In some embodiments, the two screen-printed metal pastes are provided in lieu of a color changing dye.

[0065] In an aspect of the disclosure, a sample collector is provided, comprising a handle, a flexible connector that is more flexible than the handle), and a loop, wherein the flexible connector couples the handle to the loop. In some embodiments, the loop is sized and dimensioned to collect a liquid sample of a defined volume and retain it by surface tension forces. In some embodiments, the loop is circular, oval, or polygonal. In some embodiments, the loop has a length L3 of 1-10mm or any other suitable length. In some embodiments, the flexible portion has a length L2 of 20-40mm, between 25-35mm, or any other suitable length. In some embodiments, the handle portion has a length Li of 80-160mm, or between 100-150mm, between 115-125mm, or any other suitable length. In some embodiments, the sample collector is made of an inert sterile plastic. In some embodiments the flexible connector is made from the same material as the handle portion but is thinner for increased flexibility. In some embodiments, the loop can be round, circular, oval, hexagonal, octagonal, or any other suitable shape. In some embodiments, the loop is of a size sufficient to collect and retain by surface tension forces (e.g., for at least 2 seconds, for at least 5 seconds, for at least 10 seconds, for at least 25 seconds, for at least 30 seconds) a liquid sample of a defined volume (e.g., between 0.5-20pL, between 0.5- 5pL, between l-5pL, between l-3pL, between 3-5pL, between 2-4pL, or any other suitable volume. In some embodiments, the loop comprises an empty center. In some embodiments, a mesh material is positioned within the loop. In some embodiments, a porous material is positioned within the loop.

[0066] In an aspect of the disclosure, a sample collector is provided comprising a loop configured to collect a liquid sample and at least temporarily retain it by surface tension forces. It should be appreciated that in some embodiments, a loop can be coupled to a handle without a flexible connector. It should also be appreciated that in some embodiments, a loop can be coupled to a flexible piece without a separate less-flexible piece.

[0067] Figure 15A illustrates a sample collection loop device having handle 1510A, flexible connector 1520A, and a round loop 1530A. Figure 15B illustrates a sample collection loop device having handle 1510B, flexible connector 1520B, and a hexagonal loop 1530B. Figure 15C illustrates a sample collection loop device having handle 1510C, flexible connector 1520C, and an octagonal loop 1530C. As shown in Figures 17A-17C, a tear sample collection loop of a device (e.g., a device of any of Figures 15 A, 15B, and 15C) can be empty or include a mesh or porous material. The loop itself can comprise a square or rectangular cross-section such that when the loop is cut centrally, there are two rectangular end-portions having any suitable lengths L3 and L4 (e.g., l-5mm) for uniform sample collection and retention. Figure 17A illustrates an empty round loop. Figure 17B illustrates a round loop with mesh material made of hydrophilized surface material, resembling multiple short capillaries. Mesh capillaries can be, among other shapes, round, square, hexagonal, or octagonal in cross-section. Figure 17C illustrates a round loop with porous hydrophilized surface low protein binding material positioned within the loop. In some embodiments, a loop is entirely filled by a mesh, porous or other material such that an entire inner surface of the loop is in direct contact with a portion of the material. In some embodiments, the mesh, porous or other material has a thickness that is about the same as a thickness of the loop (L3). In some embodiments, the mesh, porous or other material has a thickness that is smaller or greater than the thickness of the loop (L3). [0068] Figure 16A illustrates the use of a sample collection loop device, comprising sample collection, sample transfer and release into dilution buffer, and transferring diluted sample into an analytical device. Figure 16B illustrates the use of a sample collection loop device without sample dilution, comprising sample collection, and transferring and releasing the undiluted sample into the analytic device, for example, by contacting the loop portion with the sample receiving port. In some embodiments, it is contemplated that the loop portion can be inserted into a slot (e.g., slot 1210, or 1220) of a test cassette.

[0069] Non-Limiting Embodiments.

[0070] Embodiment 1. A sample collector, comprising a first component having an indicator zone and a collection zone, wherein the indicator zone is configured to visibly change color when a target sample collected via the collection zone reaches the indicator zone.

[0071] Embodiment 2. The sample collector of embodiment 1, wherein the indicator zone comprises at least one of a color changing dye band and embedded fibers of a first color, wherein the first color is different from a second color of the first component.

[0072] Embodiment 3. The sample collector of any of embodiments 1-2, wherein the color changing dye changes color based on a pH of a sample contacting the dye.

[0073] Embodiment 4. The sample collector of any of embodiments 1-3, wherein the first component comprises an absorbent piece of material.

[0074] Embodiment 5. The sample collector of any of embodiments 1-4, wherein the indicator zone comprises an absorbent piece of material and the collection zone comprises a mesh material.

[0075] Embodiment 6. The sample collector of any of embodiments 1-5, further comprising a second component having upper and lower pieces of material, wherein the first component is at least partially sandwiched between the upper and lower pieces of material of the second component.

[0076] Embodiment 7. The sample collector of any of embodiments 1-6, wherein the second component is configured to prevent a dye of the indicator zone from contacting an eye of a subject during tear sample collection.

[0077] Embodiment 8. The sample collector of any of embodiments 1-7, wherein the mesh material is configured to hold a sample by capillary action, wherein the sample is a liquid. [0078] Embodiment 9. The sample collector of any of embodiments 1-8, wherein the first component comprises an absorbent material along a full length of the first component extending across the indicator and collection zones. [0079] Embodiment 10. A sample collector, comprising upper and lower transparent pieces of material, and an absorbent piece of material coupled to at least one of the upper and lower transparent pieces of material, wherein a portion of the absorbent piece of material comprises a color changing dye.

[0080] Embodiment 11. The sample collector of embodiment 10, further comprising a stopper sized and dimensioned to prevent insertion of the tear sampler into a cassette slot beyond a predetermined length.

[0081] Embodiment 12. The sample collector of any of embodiments 10-11, wherein the stopper is formed by the upper and lower transparent pieces of material having a greater width than at least a portion of the absorbent piece of material.

[0082] Embodiment 13. A sample collector, comprising a handle, a flexible connector, and a loop, wherein the flexible connector couples the handle to the loop.

[0083] Embodiment 14. The sample collector of embodiment 13, wherein the loop is sized and dimensioned to collect a liquid sample of a defined volume and retain it by surface tension forces.

[0084] Embodiment 15. The sample collector of any of embodiments 13-14, wherein the loop is circular, oval, or polygonal.

[0085] Embodiment 16. The sample collector of any of embodiments 13-15, wherein the loop has a diameter of l-10mm.

[0086] Embodiment 17. The sample collector of any of embodiments 13-16, wherein the loop comprises an empty center.

[0087] Embodiment 18. The sample collector of any of embodiments 13-17, further comprising a mesh material positioned within the loop.

[0088] Embodiment 19. The sample collector of any of embodiments 13-18, further comprising a porous material positioned within the loop.

[0089] Embodiment 20. A sample collector, comprising a loop configured to collect a liquid sample and at least temporarily retain it by surface tension forces.

[0090] Embodiment 21. A sample collector, comprising an indicator zone comprising a color changing dye, wherein the color changing dye is configured to change color in the presence of a target sample.

[0091] Embodiment 22. The sample collector of embodiment 21, wherein the dye comprises a Bromocresol green dye.

[0092] Embodiment 23. The sample collector of any of embodiments 21-22, wherein the indicator zone comprises a fill line indicator zone. [0093] Embodiment 24. The sample collector of any of embodiments 21-23, wherein the collector is an absorbent piece of material.

[0094] Embodiment 25. The sample collector of any of embodiments 21-24, wherein the collector comprises a strip.

[0095] Embodiment 26. The sample collector of any of embodiments 21-25, wherein at least a portion of the collector is sized and dimensioned for inserting in a sample receiving port of an assay.

[0096] Embodiment 27. The sample collector of any of embodiments 21 -26, comprising a strip having the indicator zone comprising the color changing dye, and wherein the strip further comprises a collection zone upstream of the indicator zone

[0097] Embodiment 28. The sample collector of any of embodiments 21-27, further comprising a handle portion, wherein the indicator zone is between the handle portion and the collection zone.

[0098] Embodiment 29. An assay cassette for receiving a sample collector, comprising an upper surface having a first opening to a first compartment, and a side surface having a second opening to the first compartment, wherein the second opening is sized and dimensioned to allow a first portion of the sample collector holding a sample to be placed in the first compartment.

[0099] Embodiment 30. The assay cassette of embodiment 29, wherein the first opening is sized and dimensioned to allow a running buffer to be added into the first compartment directly onto the first portion of the sample collector.

[0100] Embodiment 31. The assay cassette of any of embodiments 29-30, wherein when the first portion of the sample collector is positioned in the first compartment, a second portion of the sample collector is positioned outside of the first compartment.

[0101] Embodiment 32. The assay cassette of any of embodiments 29-31, wherein the upper surface further comprises a window providing visibility to a test strip in the assay cassette. [0102] Embodiment 33. The assay cassette of any of embodiments 29-32, wherein the sample collector comprises any of the sample collectors of any of embodiments 1-28, and 39- 43.

[0103] Embodiment 34. A sample collector, comprising upper and lower pieces of material, and an absorbent piece of material coupled to at least one of the upper and lower pieces of material, wherein the at least one of the upper and lower pieces of material comprises a first electrode printed or otherwise positioned thereon, and a second electrode printed or otherwise positioned thereon, wherein the first electrode is made from a first metal, and wherein the second electrode is made from a second metal different from the first metal. [0104] Embodiment 35. The sample collector of embodiment 34, further comprising a first light coupled to the first and second electrodes.

[0105] Embodiment 36. The sample collector of any of embodiments 34-35, wherein the first light comprises a low power LED light.

[0106] Embodiment 37. The sample collector of any of embodiments 34-36, wherein when a sufficient tear sample is present on the absorbent piece of material, the tear sample reaches the first and second electrodes causing a small current to be created to cause the first light to light up.

[0107] Embodiment 38. The sample collector of any of embodiments 34-37, wherein the first metal comprises zinc and the second metal comprises copper.

[0108] Embodiment 39. A laminated sample collector, comprising a first piece of material, a second piece of material, and an absorbent material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent material comprises a color changing zone comprising at least one of a color changing dye and embedded fibers of a first color, wherein the first color is different from a second color of the absorbent material.

[0109] Embodiment 40. The laminated sample collector of embodiment 39, wherein the color changing dye comprises a sulfonephthalein.

[0110] Embodiment 41. The laminated sample collector of any of embodiments 39-40, wherein the color changing dye comprises a Bromocresol green dye.

[0111] Embodiment 42. The laminated sample collector of any of embodiments 39-41, wherein the color changing dye is configured to change in color when a target sample contacts the dye, and wherein the target sample comprises a tear sample.

[0112] Embodiment 43. The laminated sample collector of any of embodiments 39-42, wherein a sandwiched portion of the absorbent piece of material comprises the color changing dye band, and wherein each of the first and second pieces of material is transparent.

[0113] Embodiment 44. A laminated card, comprising a first piece of material, a second piece of material, and an absorbent piece of material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent piece of material comprises a color changing dye zone comprising at least one of a color changing dye and embedded fibers of a first color, wherein the first color is different from a second color of the absorbent piece of material, wherein the laminated card is sized and dimensioned to form a plurality of laminated sample collectors. [0114] Embodiment 45. The laminated card of embodiment 44, wherein the laminated card is scored.

[0115] Embodiment 46. The laminated card of any of embodiments 44-45, wherein the laminated card has thinned portions including a first thinned portion, and wherein the first thinned portion separates a first laminated sample collector of the plurality of sample collectors from a second sample collector of the plurality of sample collectors.

[0116] Embodiment 47. A method of collecting a tear sample, comprising contacting the collection zone (e.g., tip) of the first component of a sample collector of any of embodiments 1-9 with a portion of an eye of a subject, observing a color change of the indicator zone, determining that a suitable amount of a target sample has been collected based at least in part on observing the color change of the indicator zone.

[0117] Embodiment 48. A method of collecting a tear sample, comprising contacting a tip of the absorbent piece of material of a sample collector of any of embodiments 10-19 with a portion of an eye of a subject, observing a color change of the portion of the absorbent piece of material comprising the color changing dye, determining that a suitable amount of a target sample has been collected based at least in part on observing the color change.

[0118] Embodiment 49. A method of collecting a tear sample, comprising contacting a tip of the absorbent piece of material of a sample collector of any of embodiments 34-37 with a portion of an eye of a subject, observing a light of the sample collector turn on, determining that a suitable amount of a target sample has been collected based at least in part on observing the light turn on.

[0119] Embodiment 50. A method of collecting a tear sample, comprising contacting a tip of the absorbent material of a sample collector of any of embodiments 39-46 with a portion of an eye of a subject, observing a color change of at least a portion of the color changing zone, determining that a suitable amount of a target sample has been collected based at least in part on observing the color change.

[0120] Thus, specific examples of sample collection devices, test kits, and related systems and methods have been described. The preceding detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art and that the scope of the present invention is accordingly not limited.

[0121] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. Aspects described in connection with one embodiment are intended to be able to be used with the other embodiments. Any explanation in connection with one embodiment applies to similar features of the other embodiments, and elements of multiple embodiments can be combined to form other embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

[0122] The illustrations may include exaggerated dimensions and graphical representation to better illustrate the referenced items shown, and are not considered limiting unless expressly stated as such.

[0123] Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

[0124] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims can be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.

[0125] Also, as used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).

[0126] Reference throughout this specification to “an embodiment” or “an implementation” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment or implementation. Thus, appearances of the phrases “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment or a single exclusive embodiment. Furthermore, the particular features, structures, or characteristics described herein may be combined in any suitable manner in one or more embodiments or one or more implementations.

[0127] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more.

[0128] Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints and open-ended ranges should be interpreted to include only commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0129] Certain numerical values and ranges are presented herein with numerical values being preceded by the term “about.” The term “about” is used herein to provide literal support for the exact number that it precedes, as well as a number that is near to or approximately the number that the term precedes. In determining whether a number is near to or approximately a specifically recited number, the near or approximating un-recited number may be a number which, in the context in which it is presented, provides the substantial equivalent of the specifically recited number.

[0130] Combinations, described herein, such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof’ include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of

A, B, and C,” and “A, B, C, or any combination thereof’ may be A only, B only, C only, A and

B, A and C, B and C, or A and B and C, and any such combination may contain one or more members of its constituents A, B, and/or C. For example, a combination of A and B may comprise one A and multiple B’s, multiple A’s and one B, or multiple A’s and multiple B’s.

[0131] All structural and functional equivalents to the components of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims

1. A sample collector, comprising: a first component having an indicator zone and a collection zone, wherein the indicator zone is configured to visibly change color when a target sample collected via the collection zone reaches the indicator zone.

2. The sample collector of claim 1, wherein the indicator zone comprises at least one of a color changing dye band and embedded fibers of a first color, wherein the first color is different from a second color of the first component.

3. The sample collector of claim 1, wherein the color changing dye changes color based on a pH of a sample contacting the dye.

4. The sample collector of claim 1, wherein the first component comprises an absorbent piece of material.

5. The sample collector of claim 1, wherein the indicator zone comprises an absorbent piece of material and the collection zone comprises a mesh material.

6. The sample collector of claim 1, further comprising a second component having upper and lower pieces of material, wherein the first component is at least partially sandwiched between the upper and lower pieces of material of the second component.

7. The sample collector of claim 1, wherein the second component is configured to prevent a dye of the indicator zone from contacting an eye of a subject during tear sample collection.

8. The sample collector claim 5, wherein the mesh material is configured to hold a sample by capillary action, wherein the sample is a liquid.

9. The sample collector of claim 1, wherein the first component comprises an absorbent material along a full length of the first component extending across the indicator and collection zones.

10. A laminated sample collector, comprising: a first piece of material; a second piece of material; and an absorbent material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent material comprises a color changing zone comprising at least one of a color changing dye and embedded fibers of a first color, wherein the first color is different from a second color of the absorbent material.

11. The laminated sample collector of claim 10, wherein the color changing dye comprises a sulfonephthalein.

12. The laminated sample collector of claim 11, wherein the color changing dye comprises a Bromocresol green dye.

13. The laminated sample collector of claim 10, wherein the color changing dye is configured to change in color when a target sample contacts the dye, and wherein the target sample comprises a tear sample.

14. The laminated sample collector of claim 10, wherein a sandwiched portion of the absorbent piece of material comprises the color changing dye band, and wherein each of the first and second pieces of material is transparent.

15. A laminated card, comprising: a first piece of material; a second piece of material; an absorbent piece of material at least partially sandwiched between the first and second pieces of material, wherein a portion of the absorbent piece of material comprises a color changing dye zone comprising at least one of a color changing dye and embedded fibers of a first color, wherein the first color is different from a second color of the absorbent piece of material; and wherein the laminated card is sized and dimensioned to form a plurality of laminated sample collectors.

16. The laminated card of claim 15, wherein the laminated card is scored.

17. The laminated card of claim 15, wherein the laminated card has thinned portions including a first thinned portion, and wherein the first thinned portion separates a first laminated sample collector of the plurality of sample collectors from a second sample collector of the plurality of sample collectors.

18. A sample collector, comprising: upper and lower transparent pieces of material; and an absorbent piece of material coupled to at least one of the upper and lower transparent pieces of material, wherein a portion of the absorbent piece of material comprises a color changing dye.

19. The sample collector of claim 18, further comprising a stopper sized and dimensioned to prevent insertion of the tear sampler into a cassette slot beyond a predetermined length.

20. An assay cassette for receiving a sample collector, comprising: an upper surface having a first opening to a first compartment; and a side surface having a second opening to the first compartment, wherein the second opening is sized and dimensioned to allow a first portion of the sample collector holding a sample to be placed in the first compartment.

21. The assay cassette of claim 20, wherein the first opening is sized and dimensioned to allow a running buffer to be added into the first compartment directly onto the first portion of the sample collector.

22. A sample collector, comprising: a handle; a flexible connector; a loop; and wherein the flexible connector couples the handle to the loop.

23. The sample collector of claim 22, wherein the loop is sized and dimensioned to collect a liquid sample of a defined volume and retain it by surface tension forces.

24. The sample collector of claim 22, wherein the loop is circular, oval, or polygonal.

25. The sample collector of claim 22, wherein the loop has a diameter of l-10mm.

26. The sample collector of claim 22, wherein the loop comprises an empty center.

27. The sample collector of claim 22, further comprising a mesh material positioned within the loop.

28. The sample collector of claim 22, further comprising a porous material positioned within the loop.

29. A sample collector, comprising a loop configured to collect a liquid sample and at least temporarily retain it by surface tension forces.

30. A sample collector, comprising: upper and lower pieces of material; and an absorbent piece of material coupled to at least one of the upper and lower pieces of material, wherein the at least one of the upper and lower pieces of material comprises a first electrode printed or otherwise positioned thereon, and a second electrode printed or otherwise positioned thereon, wherein the first electrode is made from a first metal, and wherein the second electrode is made from a second metal different from the first metal.

31. The sample collector of claim 30, further comprising a first light coupled to the first and second electrodes.

32. The sample collector of claim 31, wherein the first light comprises a low power LED light.

33. A sample collector, comprising: an indicator zone comprising a color changing dye; and wherein the color changing dye is configured to change color in the presence of a target sample.

34. The sample collector of claim 33, wherein the dye comprises a Bromocresol green dye.