WO2023173002A2

WO2023173002A2 - Diagnostic test devices, systems, and methods using anti‑fogging agents

Info

Publication number: WO2023173002A2
Application number: PCT/US2023/064018
Authority: WO
Inventors: James R. Petisce; Ashlyn YOUNG; Luke PETERKEN
Original assignee: Becton Dickinson and Co
Current assignee: Becton Dickinson and Co
Priority date: 2022-03-11
Filing date: 2023-03-09
Publication date: 2023-09-14
Anticipated expiration: 2024-09-11
Also published as: WO2023173002A3

Abstract

Diagnostic test devices, systems, and methods including an anti-fogging agent are disclosed. In one aspect, a diagnostic test device includes a reaction chamber, which includes a plastic and an anti-fogging agent. The anti-fogging agent is configured to increase surface wettability of the plastic, thereby minimizing sample-containing fluid present in the form of fogging and/or droplets on the walls of the reaction chamber. Embodiments of the diagnostic test device can increase an amount of sample available to an assay reaction, which in one example embodiment occurs within a volume of fluid at the bottom of the reaction chamber.

Description

DIAGNOSTIC TEST DEVICES, SYSTEMS, AND METHODS USING ANTI-FOGGING AGENTS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/319138, filed March 11, 2022, which is hereby incorporated by reference in its entirety.

BACKGROUND

Field

[0002] The present disclosure relates to optimizing transfer of a sample solution within a consumable for diagnostic tests, and in particular nucleic-acid diagnostic tests. More particularly, the present disclosure relates to devices and methods for optimizing a volume of sample solution that moves from a sample preparation reservoir into a portion of a diagnostic test reservoir configured to receive heat and light energy for detection of an analyte of interest in the sample solution.

Description of the Related Art

[0003] Consumable diagnostic tests are disposable, single-use devices that can be targeted to the Point of Care market, where ease of use, simplicity, and cost-per-consumable arc important considerations. Consumables can be formed of polypropylene, a plastic that is easily molded to form mass-produced parts having high chemical resistance, and which is readily available at relatively low cost. In nucleic acid-based diagnostic tests, elution lysis buffer (ELB) is commonly provided to elute a test specimen from a sample collection device, such as a swab, and to release genomic material from the test specimen for molecular diagnostic testing. ELB is frequently a water-based solution. Consequently, the ELB’s characteristically high polarity can interact with the relatively low polarity polypropylene of a consumable diagnostic test in a way that inhibits test performance. For example, droplets of the ELB may adhere to a surface formed of polypropylene due to poor wetting of the polypropylene, causing a smaller quantity of ELB to be available for testing. Accordingly, there is a need for improvement in many aspects of consumable diagnostic tests, and in particular nucleic acid-based diagnostic tests that use water-based solutions to extract and test nucleic acids of interest.

SUMMARY

[0004] The devices, systems, and methods of the present disclosure each have several innovative aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure, its more prominent features will now be discussed briefly.

[0005] In one embodiment, a diagnostic test device is provided. The diagnostic test device includes a cartridge body including a sample preparation reservoir. The diagnostic test device also includes a diagnostic test reservoir coupled to the cartridge body, the diagnostic test reservoir including at least one chamber configured to receive a fluid from the sample preparation reservoir. The at least one chamber includes a plastic and an anti-fogging agent, the anti-fogging agent configured to increase the surface wettability of the plastic.

[0006] The anti-fogging agent can be configured to inhibit droplets of the fluid from adhering to interior surfaces of the at least one chamber when the fluid is dispensed into the at least one chamber from the sample preparation reservoir. The anti-fogging agent can be blended with the plastic. The anti-fogging agent can include a hydrophobic portion and a hydrophilic portion. The at least one chamber can be formed by injection-molding the plastic compounded with the anti-fogging agent.

[0007] The diagnostic test device can include a lyophilized reagent within the at least one chamber. The lyophilized reagent can include nucleic acid amplification primers. The lyophilized reagent can include a nucleic acid amplification detection probe. The diagnostic device can include a seal between the sample preparation reservoir and the at least one chamber, the seal configured to prevent movement of the fluid between the sample preparation reservoir and the at least one chamber. The diagnostic device can include a dispensing mechanism configured to break the seal to allow movement of the fluid from the sample preparation reservoir into the at least one chamber.

[0008] The diagnostic test device can include the fluid. The fluid can include a water-based buffer solution. The water-based buffer solution can include at least one of: an RBCC, a GRBS, and SDS. The sample preparation reservoir can be configured to receive a test sample. The sample preparation reservoir can be configured to receive a swab including the test sample. At least a portion of the fluid and at least a portion of the test sample can be configured to move from the sample preparation reservoir to the at least one chamber. In any of the above-recited embodiments, the at least one chamber can include two tubes. In any of the above-recited embodiments, the plastic can include polypropylene. In any of the above-recited embodiments, the at least one chamber can include a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and the anti-fogging agent can be configured to increase a volume of the fluid that is collected in the second end.

[0009] In another embodiment, a method of performing a diagnostic test using a diagnostic test device is provided. The diagnostic test device includes a sample preparation reservoir and a diagnostic test reservoir. The method includes dispensing a fluid from the sample preparation reservoir into at least one chamber of the diagnostic test reservoir. The at least one chamber includes a plastic and an anti-fogging agent, the anti-fogging agent configured to increase the surface wettability of the plastic. The method also includes performing an amplification reaction in the at least one chamber, and detecting the presence or absence of an analyte of interest in the at least one chamber.

[0010] The method can include adding a test sample to the fluid in the sample preparation reservoir before dispensing the fluid into the at least one chamber. The method can include rehydrating a lyophilized reagent in the at least one chamber with the fluid dispensed from the sample preparation reservoir. Performing an amplification reaction can include applying heat to the at least one chamber. Detecting the presence or absence of the analyte of interest can include detecting changes in fluorescence indicative of a test result. In any of the above-recited embodiments, the plastic can include polypropylene. In any of the above-recited embodiments, the at least one chamber can include a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and the anti-fogging agent can be configured to increase a volume of the fluid that is collected in the second end.

[0011] In a further embodiment, a diagnostic test device is provided. The diagnostic test device includes a cartridge body including a sample preparation reservoir, and a diagnostic test reservoir coupled to the cartridge body. The diagnostic test reservoir includes at least one chamber including a plastic and configured to receive a fluid from a sample preparation reservoir. An interior surface of the at least one chamber is treated with an agent configured to inhibit droplets of the fluid from adhering to the interior surface of the at least one chamber.

[0012] The agent can be configured to modify surface polarity of the interior surface of the at least one chamber. In any of the above-recited embodiments, the agent can be configured to increase surface wettability of the interior surface of the at least one chamber. In any of the above-recited embodiments, the agent can include parylene, polytetrafluoroethylene (PTFE), polydimethylsiloxane (PDMS), or silicon dioxide (SiCh).

[0013] In any of the above-recited embodiments, the diagnostic test device can include a lyophilized reagent within the at least one chamber. The lyophilized reagent can include nucleic acid amplification primers. The lyophilized reagent can include a nucleic acid amplification detection probe. In any of the above-recited embodiments, the diagnostic test device can include a seal between the sample preparation reservoir and the at least one chamber, the seal configured to prevent movement of the fluid between the sample preparation reservoir and the at least one chamber. The diagnostic test device can include a dispensing mechanism configured to break the seal to allow movement of the fluid from the sample preparation reservoir into the at least one chamber. In any of the above-recited embodiments, the plastic can include polypropylene. In any of the above-recited embodiments, the at least one chamber can include a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and the agent can be configured to increase a volume of the fluid that is collected in the second end.

[0014] In still a further embodiment, a method of performing a diagnostic test using a diagnostic test device is provided. The diagnostic test device includes a sample preparation reservoir and a diagnostic test reservoir. The method includes dispensing a fluid from the sample preparation reservoir into at least one chamber of the diagnostic test reservoir. An interior surface of the at least one chamber is treated with an agent configured to inhibit droplets of the fluid from adhering to the interior surface of the at least one chamber. The method also includes performing an amplification reaction in the at least one chamber, and detecting the presence or absence of an analyte of interest in the at least one chamber.

[0015] The method can include adding a test sample to the fluid in the sample preparation reservoir before dispensing the fluid into the at least one chamber. The method can include rehydrating a lyophilized reagent in the at least one chamber with the fluid dispensed from the sample preparation reservoir. Performing an amplification reaction can include applying heat to the at least one chamber. Detecting the presence or absence of the analyte of interest can include detecting changes in fluorescence indicative of a test result. In any of the above-recited embodiments, the plastic can include polypropylene. In any of the above-recited embodiments, the at least one chamber can include a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and the agent can be configured to increase a volume of the fluid that is collected in the second end.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above-mentioned aspects, as well as other features, aspects, and advantages of embodiments of the present disclosure will now be described in connection with various implementations, with reference to the accompanying drawings. The illustrated implementations are merely examples and are not intended to be limiting. Throughout the drawings, similar symbols typically identify similar components, unless context dictates otherwise.

[0017] FIGs. 1A-1C illustrate examples of fogging or droplet formation in devices not including an anti-fogging agent in accordance with the present disclosure.

[0018] FIG. 2 illustrates one embodiment of a device including an anti-fogging agent in accordance with the present disclosure.

[0019] FIG. 3 is a close-up view of the device of FIG. 2, schematically illustrating an embodiment where a polar portion of an anti-fogging agent has bloomed to the interior surface of a reaction chamber in accordance with the present disclosure.

[0020] FIG. 4A illustrates a sorbitan monostearate molecule.

[0021] FIG. 4B illustrates a sorbitan molecule.

[0022] FIG. 5 schematically illustrates an embodiment where a polar portion of sorbitan monostearate, an example anti-fogging agent, has bloomed to the interior surface of a reaction chamber in accordance with the present disclosure.

[0023] FIG. 6A illustrates a triglycerol monostearate.

[0024] FIG. 6B illustrates a glycerol molecule. [0025] FTG. 6C illustrates a triglycerol molecule.

[0026] FIG. 7 A illustrates an example dispense assembly oriented for insertion into an example cartridge in accordance with an embodiment of the present disclosure.

[0027] FIG. 7B illustrates a view of the example cartridge of FIG. 7A in accordance with the present disclosure.

[0028] FIG. 7C illustrates an exploded view of the example dispense assembly of FIG. 7A in accordance with the present disclosure.

[0029] FIG. 7D illustrates a cross-sectional view of the example cartridge of FIG. 7A received in a diagnostic test instrument including heat blocks.

[0030] FIG. 8 illustrates an example dual tube including an anti-fogging agent and a pellet which includes dried reagents and/or a mixing bead, in accordance with the present disclosure.

[0031] FIG. 9 illustrates an example method for performing a diagnostic test using a diagnostic test device in accordance with an embodiment of the present disclosure.

[0032] FIG. 10A is a graph plotting retained volume of liquid in dual tubes, including dual tubes having various material modifications according to the present disclosure.

[0033] FIGs. 10B-10C are graphs plotting process capability of untreated polypropylene dual tubes and of polypropylene dual tubes including an anti-fogging additive, respectively, in accordance with the present disclosure.

DETAILED DESCRIPTION

[0034] Embodiments of the present disclosure provide devices, systems, and methods capable of optimizing transfer of a solution, such as a sample solution, from one portion of a diagnostic test device to another portion of the device. The solution can include a high polarity liquid, such as a water-based solution, that tends to be retained on a surface formed of a low polarity material, such as a plastic surface, when the solution comes into contact with, or otherwise interacts with, the surface. The surface can include, for example, a surface of a component formed of polypropylene, and the solution may pass across or along the surface as it is being transferred within the diagnostic test device. Embodiments of the present disclosure include surfaces having an anti-fogging agent that can advantageously decrease the tendency of the solution to create droplets or fogging on the surface during transfer from one portion of the diagnostic test device to another portion of the device. Reducing or eliminating a variable, uncontrolled, and/or inefficient transfer of the solution using embodiments of an anti-fogging agent can increase a volume of the solution that is received in a portion of the diagnostic test device where testing occurs. For example, embodiments of the present disclosure can advantageously increase a volume of solution that is transferred within a diagnostic test device from a sample preparation reservoir to a test reservoir, where heat and/or light energy are delivered to perform a diagnostic test. Advantageously, increasing the volume of solution that is reliably and consistently delivered to the test reservoir using embodiments of the present disclosure can increase the quantity of analyte of interest that is included in an assay or other test reaction, contributing to diagnostic test results having higher accuracy and specificity.

[0035] Accordingly, embodiments of the diagnostic test devices, systems, and methods according to the present disclosure can minimize or eliminate sample-containing fluid present in the form of fogging and/or droplets on the walls of a test reservoir, such as a reaction chamber. Embodiments of the diagnostic test devices, systems, and methods disclosed herein can thus advantageously increase an amount of sample available to an assay reaction, which in one example embodiment occurs within a volume of fluid that is received and/or collected at the bottom of the reaction chamber.

[0036] Throughout the following description, various embodiments will be described with reference to an example implementation of a rapid, nucleic acid-based diagnostic system that may test for a variety of diseases. As illustrative examples, the system may test for sexually transmitted infections (STIs), such as gonorrhea and chlamydia, and respiratory tract infections (RTIs), such as influenza A or B. The example system is targeted to the Point of Care (POC) market where ease of use, simplicity, CLIA waivability and rapid turnaround time (TAT) of results are considerations. It will be understood, however, that any of the devices, systems, and methods described herein may be applied to any other medical, forensic, or other application.

[0037] In many instances, the elution lysis buffer (ELB) used in diagnostic testing platforms is a water-based solution. Consumables used in diagnostic testing — such as but not limited to cartridges, tubes, or reaction chambers — are often formed of or include a plastic such as polypropylene or polyethylene. Plastics that are commonly implemented, such as polypropylene and polyethylene, are relatively low-polarity materials. Consequently, ELB’s characteristic high polarity may cause beading on the surface of plastic components of consumables, such as a reaction chamber configured to receive a solution.

[0038] This interaction can cause less than an optimal quantity of solution to be available for testing in the diagnostic testing platform. For instance, ELB containing harvested patient sample may bead up and/or fog on the relatively low polarity plastic (in this nonlimiting example polypropylene) on the interior surface of a reaction chamber wall. FIGs. 1A- 1C illustrate this phenomenon. For example, a test reservoir 102 may contain two reaction chambers 110, each including an interior surface 112. Though some of the ELB solution 106 may be dispersed to the bottom of the reaction chamber 110, some of the ELB solution may remain on the upper portion of the interior surfaces 112, present in the form of droplets 108 and fogging 104. In these examples, the volume of ELB solution 106 at the bottom of the reaction chamber 110 is reduced because a portion of the ELB containing harvested patient sample is present in droplets 108 or fogging 104, rather than the volume of ELB solution 106 at the bottom of the reaction chamber 110.

[0039] In FIG. 1A, the volume of ELB solution 106 at the bottom of the reaction chambers 110 is reduced because dispersed ELB is present in droplets 108 and fogging 104. ELB may be dispersed from the top of the reaction chambers 110 and may fall or flow down to the bottom of the chambers 110. Frequently, however, some volume of ELB remains on the upper portion of surface 112 of chambers 110, present as fogging 104 and droplets 108 as illustrated. The volume of ELB solution 106 at the bottom of each chamber 110 is unequal due to unequal droplet formation and fogging between the two chambers 110.

[0040] In FIG. IB, a portion of the volume of ELB solution dispensed into the reaction chambers 110 is present in the form of droplets 108. The volume by which ELB solution 106 at the bottom of the chambers 110 is reduced is related to the volume of droplets 108. In FIG. IB, the droplets are not of the same volume, so the ELB solution 106 at the bottom of each chamber 110 is unequal. As illustrated, the droplet 108 on the surface 112 of the left chamber 110 is larger than the droplet 108 on the surface 112 of the right chamber 110, and accordingly the volume of ELB solution 106 at the bottom of the left chamber 110 is less than the ELB solution 106 at the bottom of the right chamber 110. [0041] Tn FIG. 1 C, a volume of ELB solution 106 at the bottom of the reaction chambers 110 is reduced, because a portion of the ELB solution dispensed into the reaction chambers 110 is present in droplets 108 formed at the top corners of the reaction chambers 110. ELB solution may be dispensed from the top of the reaction chambers 110 and may fall or flow down to the bottom of the chambers 110. However, dispensed ELB solution frequently collects in the top corners, as shown in FIG. 1C. The geometry of the top comer of a reaction chamber 110 provides two surfaces to which a droplet 108 may adhere. Again, the formation of droplets 108 reduces the volume of ELB solution 106 present at the bottom of chambers 110.

[0042] The droplet formation and/or fogging of the ELB solution may result in relatively variable amounts of sample-containing ELB solution at the bottom of the reaction chamber, where there may be reagents for an assay reaction. The beading and/or fogging may also cause unintended variability in the amount of harvested test specimen available for the assay reaction. This, in turn, may cause inaccuracy in assay results since the amount (for example, volume) of test specimen available to the assay reaction is not well controlled. This variability may be particularly acute in instances where the test specimen is delivered from one reservoir to another reservoir, such as reaction chamber 110, in a way that exposes the ELB solution to surfaces, such as interior surfaces 112 of reaction chamber 110, formed of plastic.

[0043] In some instances, a sample present in the ELB solution may include genomic material. Beading and/or fogging of ELB solution may affect the amount of available genomic material, such as DNA or RNA, introduced to an amplification reaction, for example. For example, beading and/or fogging of the ELB solution can decrease the amount of genomic material present at a location in the reaction chambers 110, for example the bottom of the reaction chambers 110, where an amplification reaction within the reaction chambers 110 occurs.

[0044] In addition to decreasing sample variability, it may be desirable for ELB dispense volumes to be consistent to ensure that lyophilized reagents within the reaction chamber are reconstituted to a target concentration. As an example, beading and/or fogging leading to reduced ELB solution volume that is ultimately delivered to a target location in the diagnostic testing platform may cause lyophilized reagents to be reconstituted at a higher concentration than intended. Consequently, the assay involving these lyophilized reagents may not perform as intended.

[0045] Embodiments of the present disclosure provide devices, systems, and methods that can ensure more consistent ELB disperse volumes by minimizing or eliminating ELB beading on the inner surface of a target reservoir, such as a reaction chamber.

Devices, Systems, and Methods Using an Anti-Fogging Agent in a Diagnostic Testing Platform

[0046] Devices, systems, and methods of the present disclosure can optimize transfer of a solution, such as a sample solution, within a diagnostic test device at least partially formed of plastic by including an anti-fogging agent in the plastic material. FIG. 2 illustrates a portion of an example consumable diagnostic test device 200 implementing an anti-fogging agent according to the present disclosure. In this example, the diagnostic test device 200 includes a test reservoir formed of plastic, in this case dual tube 202. The dual tube 202 includes two reaction chambers 204 configured to receive a test specimen including ELB solution 106. Each reaction chamber 204 includes walls 210 formed of a plastic material that includes an anti-fogging agent. The walls 210 have interior surfaces 206. The anti-fogging agent may minimize or substantially eliminate beading and/or fogging of the ELB solution dispensed into the two reaction chambers 204. Consequently, ELB solution 106 at the bottom of the reaction chambers 204 may include a relatively large portion of, or substantially all of, the ELB solution dispersed into the reaction chamber 204 from another reservoir, such as a sample preparation reservoir of the diagnostic test device 200. An example sample preparation reservoir of a diagnostic test device is described in detail below with reference to FIGs. 7A-7C.

[0047] It may be desirable to maximize the proportion of dispensed ELB solution that settles to the bottom of the reaction chambers 204. For example, heat and/or optical signals related to an assay reaction, for example for amplification and detection of nucleic acids, may be directed to the bottom of the reaction chambers 204 but not to the upper portions of the reaction chambers 204. Thus, ELB solution present in droplets or fogging in the upper portions of the reaction chambers 204 may not receive heat as intended. Similarly, ELB solution present in droplets or fogging may not be properly positioned to receive and emit optical signals (or other signals used to detect assay results). Further, ensuring that ELB solution dispensed into the reaction chambers 204 is consistently and reliably dispersed to the bottom of the reaction chambers 204 may reduce variability of assay results. Consistent and reliable dispersion of ELB solution to the bottom of chambers may also ensure a higher likelihood that sufficient sample material, for example genomic material, is available to the assay reaction to ensure an accurate test result.

[0048] One way to maximize the proportion of dispensed ELB solution that settles to the bottom of reaction chamber 204 is to minimize the amount of ELB solution present on the upper portion of interior walls of reaction chambers 204. Depending on the volume of the ELB solution dispensed into the reaction chambers 204 relative to the interior volume of the reaction chambers 204, this portion of the interior walls that is undesirable for dispersion may be a relatively large surface area. In the non-limiting embodiment illustrated in FIG. 2, for example, approximately half of the vertical surface area of the interior surfaces 206 is a potential location for the ELB solution to bead and/or fog rather than be dispensed to the bottom of the reaction chambers 110, where an amplification reaction and detection take place. Embodiments of the reaction chambers 204 that include an anti-fogging agent within or on the plastic material forming the reaction chamber walls 210 can decrease the likelihood that ELB solution collects on upper portion of the reaction chamber interior surfaces 206. In this way, the anti-fogging agent may increase the volume of ELB solution that is present at the bottom of the reaction chambers 204. Reduction of beading and/or fogging thereby decreases sample variability and increases the volume of test specimen in the bottom of the reaction chamber 204 available for the amplification reaction and detection. Without being bound to any particular theory, it is believed that untreated plastic, for example polypropylene, is more prone to ELB beading or fogging because its surface is relatively hydrophobic, such that the ELB solution is less capable of sheeting off to settle at the bottom of the reaction chamber 204. Inclusion of an anti-fogging agent in the plastic of the reaction chambers 204 in accordance with embodiments of the present disclosure may help to minimize ELB solution caught or retained on the upper portion of the interior walls of the reaction chamber 204. Without being bound to any particular theory, it is believed that the anti-fogging agent may increase the hydrophilicity of the interior surface of the reaction chamber 204 such that ELB solution is more capable of “sheeting off’ to settle at the bottom of the reaction chamber 204. Thus, inclusion of an anti-fogging agent may minimize beading and/or fogging and thereby promote settling of a sample solution to the bottom of the reaction chamber 204. [0049] It will be understood that embodiments of the present disclosure are not limited to reaction chambers or other test reservoirs having a relatively large surface area where ELB solution can collect, or devices that collect ELB solution at a bottom of a test reservoir. It will also be understood that embodiments of the present disclosure are not limited to diagnostic test devices that move a solution from a sample preparation reservoir to a test reservoir. Embodiments of the present disclosure can be suitably implemented in other diagnostic testing platforms where a sample solution interacts with a plastic surface as it is transferred from one location to another location.

[0050] The plastic forming the reaction chambers 204 can be modified to include any suitable anti-fogging agent. It may be desirable to select an anti-fogging agent that includes a compound having a hydrophobic portion and a hydrophilic portion. When combined with a plastic, such as polypropylene, the polar portion of the anti-fogging agent may “bloom” to the surface of the plastic. FIG. 3 illustrates this concept in a close-up view of a portion 208 of the left reaction chamber 204 of the diagnostic test device 200 of FIG. 2. The reaction chamber 204 of the diagnostic test device 200 includes an interior surface 206 and a wall 210 according to one non-limiting embodiment of the present disclosure. As discussed above, the reaction chamber 204 is formed of a plastic, in this case polypropylene, that includes an anti-fogging agent. It will be understood that other plastics, such as polyethylene, can be suitably implemented in embodiments of the present disclosure. The anti-fogging agent includes molecules 302 having a hydrophobic portion 306 and a hydrophilic portion 304. On the reaction chamber interior surface 206, many anti-fogging agent molecules 302 are present on the reaction chamber wall 210. The polar portion of the anti-fogging agent molecules 302 have “bloomed” such that they are present on the reaction chamber interior surface 206. Without being bound to any particular theory, it is believed that the hydrophobic portion 306 may remain entangled in the plastic of reaction chamber wall 210. Hydrophilic portion 304 may be oriented inward toward a center of the reaction chamber 204. The presence of hydrophilic portion 304 on the reaction chamber interior surface 206 may increase the surface wettability of the plastic, and facilitate an ELB solution introduced into reaction chamber 204 to “sheet off’ the interior surface 206 of the reaction chamber wall 210 and flow toward a bottom of the reaction chamber 204. The anti-fogging agent may thereby reduce, inhibit, and/or prevent droplet adhesion and/or fogging on a surface, for example, on a portion of the interior surface 206 where an amplification reaction and/or detection docs not occur.

[0051] One example anti-fogging agent that can be implemented in the embodiments of the present disclosure is sorbitan monostearate, illustrated in FIG. 4A. Sorbitan monostearate 402 includes a hydrophilic portion 406 and a hydrophobic portion 404. An ester such as sorbitan monostearate 402 may be synthesized by reacting sorbitan 408 (illustrated in FIG. 4B) with a fatty acid. Illustrative examples of fatty acid include stearic acid or lauric acid. Any suitable fatty acid may be reacted with sorbitan 408 to form an anti-fogging agent according to the present disclosure. Sorbitan monostearate 402 may be desirable as an anti-fogging agent because sorbitan, which is a poly alcohol, may be made inexpensively from fruits, for example, apples.

[0052] FIG. 5 illustrates an example diagnostic testing platform 500 that includes a plastic modified with an anti-fogging agent according to the present disclosure, wherein the anti-fogging agent includes sorbitan monostearate. In this non-limiting example, the platform 500 includes a reaction chamber formed of polypropylene and is configured to receive an ELB solution at a bottom portion (not illustrated) of the reaction chamber. On a reaction chamber interior surface 502 of the diagnostic testing platform 500, many sorbitan monostearate molecules 506 are present on the reaction chamber wall 504. The polar portion of the sorbitan monostearate molecules 506 have “bloomed” to the surface of the plastic of the reaction chamber wall 504. Without being bound to any particular theory, it is believed that the long carbon tail of the fatty acid (the hydrophobic portion 508) stays entangled in the plastic of the reaction chamber wall 504. The hydrophilic portion 510 includes the sorbitan with the -OH groups. The hydrophilic portion 510 “blooms” to the polypropylene surface such that the hydrophilicity of the reaction chamber interior surface 502 is increased. This increased hydrophilicity may cause the ELB to “sheet off’ the reaction chamber interior surface 502, thereby reducing droplet adhesion or fogging on the surface 502. This interaction can increase a portion of ELB solution that is dispensed to the bottom portion of the reaction chamber where an amplification reaction and/or detection takes place, and decrease a portion of the ELB solution that is present on the interior surface 502 where the amplification reaction and/or detection does not take place. [0053] FTG. 6A illustrates triglycerol monostearate 602, another example antifogging agent that can be suitably implemented in embodiments of the present disclosure. Glycerol 608, illustrated in FIG. 6B, is another inexpensive alcohol, which can be made from soybean oil. Glycerol 608 can be polymerized with itself to form diglycerol or triglycerol 610, illustrated in FIG. 6C. Like sorbitan 408, glycerol 608 and triglycerol 610 are relatively hydrophilic. A polyglycerol may be reacted with a fatty acid to form a non-ionic surfactant. The fatty acid may be, as illustrative examples, stearic acid or lauric acid. Triglycerol monostearate 602 may be formed through such a reaction. Triglycerol monostearate 602 includes a hydrophobic portion 604 that may entangle in plastic, such as polypropylene, and a hydrophilic portion 606, including a glycercol, that may “bloom” to the surface of the plastic. Exposure of hydrophilic portion 606 on the interior surface may cause ELB to “sheet off,” thereby reducing droplet adhesion or fogging. Other suitable anti-fogging agents can be implemented in embodiments of the present disclosure, for example Atmer™ 7373 by Croda.

[0054] It will be understood that embodiments of the present disclosure are not limited to an anti-fogging agent added to or compounded with a host material forming a test reservoir. For example, it will be understood that embodiments of the present disclosure can including a plastic that has been treated or coated to reduce droplet adhesion or fogging. Nonlimiting examples of such treatments or coatings include, but are not limited to, a parylene coating; plasma or corona treatment; dip coating with polytetrafluoroethylene (PTFE); dip coating with polydimethylsiloxane (PDMS); vacuum deposition of silicon dioxide (SiCh); and treatment with Silmer® UR- 5050 (available from Siltech Corporation).

Example Diagnostic Test Device Implementing an Anti-Fogging Agent

[0055] An example diagnostic test device 700 implementing an anti-fogging agent according to the present disclosure is now described with reference to FIGs. 7A-7D. The diagnostic test device 700 is implemented in a rapid, nucleic acid-based test system capable of performing automated molecular diagnostic testing for the detection of a variety of analytes of interest. The diagnostic test device 700 includes a consumable plastic cartridge 702 that is inserted into a diagnostic instrument of the test system. A barcode on the cartridge 702 may be scanned by the diagnostic instrument to automatically identify the assay to be performed on a patient sample that is added to the cartridge 702. In this non-limiting example, the assay includes a sample preparation assay and an isothermal amplification assay for the detection of nucleic acids of interest. A user may enter patient and/or sample information via a touchscreen on the instrument or via a barcode scan. Components of the cartridge 702 and a dispense assembly 704 that may interface with the cartridge 702 are illustrated in FIGs. 7A-7C.

[0056] The cartridge 702 includes a cartridge body 710 enclosing, among other features, a sample preparation reservoir 712. In some examples, the cartridge 702 may be heated to a temperature to facilitate preparation of a sample for the assay. ELB solution, contained within the sample preparation reservoir 712 of the cartridge body 710, may also be heated as the cartridge 702 is heated. As illustrative examples, ELB may include red blood cell lysis buffer (RBCC), glycine running buffer solution (GRBS), and/or sodium dodecylsulfate solution (SDS). Once the cartridge 702 is heated to a target temperature, initial cap 716 on the cartridge 702 may be removed, for example by unscrewing the initial cap 716 from the body 710 of the cartridge 702. A specimen swab may be inserted into the sample preparation reservoir 712 containing now-heated ELB solution, and swirled to transfer a test specimen from the swab into the ELB solution. The swab may then be removed from the sample preparation reservoir 712. In other examples, the swab may be inserted into and swirled within the sample preparation reservoir 712 prior to ELB heating. In yet further examples, a sample in liquid form may be pipetted directly into the sample preparation reservoir 712. Liquid sample may include urine, blood, interstitial fluid, saliva, or any other suitable sample material. Pipetting of a liquid sample may occur before or after heating the ELB solution.

[0057] If present in the sample, particles containing analyte of interest may be lysed in the solution by the chemical action and elevated temperature of the ELB solution. In some examples, the sample preparation reservoir 712 may hold a volume of ELB solution between 0 and 5 mL, between 0.5 and 4.5 mL, between 1 and 4.0 mL, between 1.5 and 3.5 mL, between 2 and 3 mL, or any value or range within or bounded by any of these ranges or values, although values outside these values or ranges can be used in some cases. Additionally or alternatively, in some examples the sample preparation reservoir 712 may hold between 1 and 3 mL of ELB solution. The amount of ELB solution may depend on the particular assay.

[0058] In some examples, the cartridge body 710 may include a geometry to facilitate rapid heating of the contents of the sample preparation reservoir 712. For example, cartridge body 710 may have a high surface area-to-volume ratio, which may facilitate rapid heating, by having an oblong cross-section. [0059] The cartridge 702 also includes a test reservoir where amplification and detection of the analyte of interest occurs. In particular, the cartridge body 710 is coupled to a test reservoir where isothermal amplification and fluorescence detection take place. The test reservoir includes a dual tube 202, but it will be understood that other configurations can be suitably implemented. The cartridge body 710 can connect to the dual tube 202 using any number of coupling mechanism, such as but not limited to a first structure that matingly connects to a corresponding second structure on the exterior surface of the dual tube 202. The cartridge 702 also includes a dual tube gasket 706 configured to provide a seal at an interface between the cartridge body 710 and the dual tube 202. The walls of the dual tube 202 may include a polypropylene material or any other suitable material (such as, but not limited to, polyethylene). The dual tube gasket 706 may include silicone or any other suitable material. The sample preparation reservoir 712 may be separated from the reaction chamber 204 by a foil seal 708. The foil seal 708 may be heat sealed onto the cartridge body 710 and/or dual tube 202. The foil seal 708 may be pierced by a sufficient application of mechanical force.

[0060] The dual tube 202 may include two separate reaction chambers 204. Each reaction chamber 204 may hold up to 50 pL of liquid, up to 75 pL of liquid, up to 100 pL of liquid, up to 150 pL of liquid, up to 200 pL of liquid, up to 250 pL of liquid, up to 300 pL of liquid, up to 350 pL of liquid, up to 400 pL of liquid, up to 450 pL of liquid, up to 500 pL of liquid, up to 1000 pL of liquid, or any value or range within or bounded by any of these ranges or values, although values outside these values or ranges can be used in some cases. Additionally or alternatively, in some examples the reaction chamber 204 may hold 100 pL of liquid.

[0061] In some examples, each reaction chamber 204 may contain a pellet 802 of lyophilized reagents, as illustrated in FIG. 8. The lyophilized reagents within pellet 802 may include enzymes, primers, beacons, salts, and/or other reagents used in assay reactions. A bead 804 may also be included within the reaction chamber 204. The bead 804 may be embedded inside the pellet 802. Advantageously, the bead 804 may facilitate mixing of the lyophilized reagents upon rehydration of the pellet 802. For example, the bead 804 may be moved, for example under the influence of a magnetic force, within the reaction chamber 204 to cause motion within any liquid within reaction chamber 204 to aid in dissolving the lyophilized reagents. The bead 804 may include stainless steel or any other suitable material. [0062] Tn such examples, it may be desirable to ensure that a minimum of amount of ELB solution, for example a volume, is dispersed to the bottom of the reaction chamber 204 where the pellet 802 is located. For a given amount of lyophilized reagent, a minimum volume of ELB solution may be required to fully rehydrate those lyophilized reagents. In certain embodiments, the minimum volume of ELB solution required may be 250 pL, 200 pL, 150 pL, 100 pL, 50 pL, or 25 pL, or any value or range within or bounded by any of these ranges or values, although values outside these values or ranges can be used in some cases. Additionally or alternatively, in some examples the minimum volume of ELB solution to fully rehydrate the lyophilized reagents may be 80 pL.

[0063] In certain examples, the target volume of ELB solution to be dispensed to the reaction chamber 204 is 100 pL. As an illustrative example, if 100 pL of ELB solution is dispensed to a reaction chamber not including an anti-fogging agent, it is possible that 35 pL of the ELB solution is retained on the walls of the reaction chamber and only 65 pL is dispensed to the bottom of the reaction chamber to rehydrate lyophilized reagents. In this example, the volume of ELB solution dispensed to the bottom of the reaction chamber is less than the 70 pL minimum volume needed for rehydration of lyophilized reagents. This insufficient rehydration volume may render an invalid assay test result. In contrast, a reaction chamber including an anti-fogging agent according to embodiments of the present disclosure may eliminate or reduce the volume of ELB solution retained on the walls of the chamber, such that a volume of over 70 pL is dispensed to the bottom of the reaction chamber. Increasing the proportion of ELB solution dispensed to the bottom of the reaction chamber can thereby reduce the risk of an invalid assay test result.

[0064] In some examples, the dispense assembly 704 of the diagnostic test device 700 may be inserted onto the device 700. The dispense assembly 704 includes a dispense cap 726 coupled to a piercing rod 724, and a dispense insert 720 configured to interact with the piercing rod 724 to deliver a volume of sample solution from the sample preparation reservoir 712 to the dual tubes 202. The sample solution includes the ELB solution and the analyte of interest, if present, that has been released from lysed particles (“lysed sample”). The user may contact the dispense cap 726 with the threading 714 on the cartridge body 710, rotating the dispense cap 726 to screw it onto the cartridge body 710. The piercing rod 724 is configured to translate along a longitudinal axis of the sample preparation reservoir, toward the dual tubes 202, as the dispense cap 726 is rotated. As the dispense assembly 704 is inserted into and screwed onto the cartridge body 710, the piercing rod 724 translates downward toward the dual tubes 202 and penetrates the foil seal 708 separating sample preparation reservoir 712 from the reaction chambers 204. As the dispense cap 726 continues to rotate and the piercing rod 724 continues to translate downward, two “piston and cylinder” mechanisms dispense a predefined volume of ELB solution into the two reaction chambers 204. The mechanisms include the two rods of the piercing rod 724 (forming two “pistons”) and two barrel-shaped portions of the dispense insert 720 (forming two “cylinders”). The mechanisms also include grommets 722 and a dispense insert gasket 718 configured to provide seals at interfaces between the piercing rod 724, the dispense insert 720, and the dual tube 202. It will be understood that other sealing configurations can be suitably implemented.

[0065] The mechanisms may press a defined volume of ELB with lysed sample through the pierced foil seal 708. For example, the rods of the piercing rod 724 can push a defined volume of ELB solution through the barrel-shaped portions of the dispense insert 720 and into the dual tubes 202 upon piercing of the foil seal 708 by the rods. The ELB solution with analyte of interest, if present, is received in the dual tubes 202. In particular, the ELB solution with analyte of interest, if present, is collected by the reaction chambers 204 as it is dispensed from the sample preparation reservoir 712. The defined volume of ELB solution received in each reaction chamber 204 may be up to 10 pL, up to 25 pL, up to 50 pL, up to 75 pL, up to 100 pL, up to 125 pL, up to 150 pL, up to 200 pL, up to 300 pL, or any value or range within or bounded by any of these ranges or values, although values outside these values or ranges can be used in some cases. The defined volume may be less than 200 pL, less than 150 pL, less than 125 pL, less than 100 pL, less than 75 pL, less than 50 pL, less than 25 pL, or any value or range within or bounded by any of these ranges or values, although values outside these values or ranges can be used in some cases. Additionally or alternatively, in some examples the defined volume is approximately 100 pL. Additional non-limiting example implementations of the “piston and cylinder” mechanism for dispersing a volume of liquid from the sample preparation reservoir 712 to the reaction chamber 204 are described in U.S. Pub. No. 2020/0278368, incorporated herein by reference.

[0066] In certain examples, the target dispense volume from the sample preparation reservoir 712 to each of the reaction chambers 204 is 100 pL, or 200 pL total from the sample preparation reservoir 712. Tn the examples where 100 pL is the target dispense volume, 80-120 pL may be acceptable volumes to dispense to the bottom of the reaction chamber to ensure that there is enough sample present and that reagents are within their respective target concentration ranges. In other words, if the 100 pL introduced from the sample preparation reservoir to a reaction chamber, it is desirable that no more than 20 pL is retained on the upper portion of the interior surface of the reaction chamber. Embodiments of the present disclosure implementing an anti-fogging agent can ensure that, when about 200 pL of ELB solution is released from the sample preparation reservoir 712, approximately 80-100 pL of this ELB solution is received in the bottom of each of the reaction chambers 204 (that is, about 80-100 pL of ELB solution is received in each reaction chamber 204).

[0067] Intact portions of the foil seal 708 may continue to separate the contents of the cartridge body 710 from the reaction chamber 204. In addition, the compressible dispense insert gasket 718 may contact the foil seal 708 at the junction between the cartridge body 710 and the reaction chamber 204 to create a leak-proof seal, which may ensure no further ELB solution and lysed sample are introduced to the reaction chambers 204 beyond the defined volumes.

[0068] In some examples, the ELB solution and lysed sample introduced to the reaction chambers 204 may rehydrate the pellet of lyophilized reagents. When rehydrated, the reagents may react with analytes of interest, in present in the ELB solution, in accordance with a selected assay. In certain examples, the reaction is a DNA amplification reaction. In some examples, the reaction is an isothermal DNA amplification reaction.

[0069] In one non-limiting embodiment, the diagnostic instrument applies heat to the ELB solution collected in the reaction chambers 204 to perform an amplification reaction, directs optical signals to the reaction chambers 204, and receives optical signals from the reaction chambers 204 to detect an analyte of interest, if present, in the ELB solution. The diagnostic instrument may use one or more image sensors (not diagrammed) to optically scan the bottom portion of the reaction chambers 204. Such scanning may be used to detect and/or measure the volume of the ELB solution dispensed to the bottom of the reaction chambers 204. In certain examples, the ELB solution may include a dye. This dye can be used by the image sensor to visually image colored or contrasting fluid flow into the reaction chambers 204 to confirm the dispensing action and to confirm the dispense volume. Such scanning may also be used to detect and/or measure the progress of the test assay reaction. For example, the diagnostic instrument may optically scan the bottom portion of the test reaction chambers 204 to detect and/or measure changes in fluorescence indicative of an ongoing amplification reaction.

[0070] FIG. 7D illustrates a cross-sectional view of diagnostic test device 700 of FIG. 7A received in one or more heat blocks of a diagnostic instrument of a test system. The diagnostic test device 700 includes the dispense assembly 704 received in the cartridge body 702. In this non-limiting example, the cartridge body 710 is received in a heat block 730 of the diagnostic instrument, and the dual tubes 202 are received in a heat block 728 of the diagnostic instrument. The heat block 730 can apply heat to the cartridge body 702 to facilitate preparation of a sample for an assay. As described above, ELB solution, contained within the sample preparation reservoir 712 of the cartridge body 710, is heated as the cartridge 702 is heated. The heat block 728 can apply heat to the dual tubes 202, into which the ELB solution has been dispensed, to perform an amplification reaction. Windows within the heat bock 728 (not illustrated in this-cross-sectional view) can allow optical signals to be directed to the reaction chambers 204, and for optical signals to be received from the reaction chambers 204, to detect an analyte of interest, if present, in the ELB solution.

[0071] One or more image sensors incorporated within the diagnostic instrument can capture digital images of the reaction chambers 204 and the progression of the dispensing mechanism components, as well as the state and progress of the fluids contained within the cartridge. These digital images can be processed by software image analysis within the instrument controller to provide control and status outputs. The digital output from the one or more image sensors can be used to confirm the test assay progression and confirm the correct release and flow of test reagents within the cartridge such that the integrity of the test can be confirmed by the controller and used to improve the reliability and accuracy of the test result. The image sensor can be used by the controller to observe internal fluids and the mechanism parts within the cartridge, including within the reaction chambers 204, and to calculate a control interpretation through the use of image analysis by the instrument controller.

[0072] The image sensor can confirm the operation and position of the dispensing mechanism to confirm incomplete or correct and complete operation of the cartridge, and prompt the user at completion or automatically progress to a next step in the apparatus process to acquire the final test result.

[0073] The dual tubes 202 are formed of a plastic that includes an anti-fogging agent according to the present disclosure. Transfer of an ELB solution from the sample reagent reservoir 712 to the reaction chambers 204 using the “piston and cylinder” mechanism exposes the ELB solution to the interior surfaces of the reaction chambers 204. The ELB solution may be generally inclined to fog and/or bead on the upper interior surface of reaction chambers not including an anti-fogging agent. However, the reaction chambers 204 of dual tubes 202, formed from plastic including an anti-fogging agent according to the present disclosure, advantageously reduce or substantially eliminate beading and/or fogging of the ELB solution. Thus, because beading and/or fogging of the ELB solution may be reduced or substantially eliminated, all or substantially all of the dispersed ELB solution may be collected at the bottom of the reaction chambers 204, as described above with reference to FIG. 2. This is advantageous because, for embodiments of the diagnostic test device 700 including an antifogging agent according to the present disclosure, reliable and consistent delivery of optimized volumes of ELB solution from the sample reagent reservoir 712 to the reaction chambers 204 may ensure accurate assay results. In some examples, because the reaction chambers 204 are where the test assay reaction (for example DNA amplification and detection) occurs, the variability in the amount of sample available to the test assay reaction may be reduced. The reduction in sample amount variability may in turn improve test assay accuracy and specificity.

[0074] FIG. 9 illustrates an example method for performing a diagnostic test using a diagnostic test device, such as the diagnostic test device 700, in accordance with an embodiment of the present disclosure. The diagnostic test device 700 includes a diagnostic test reservoir including a plastic and an anti-fogging agent, in accordance with implementations of the present disclosure.

[0075] The method begins at a block 902, where a test sample may be added to fluid within the sample preparation reservoir 712. As described above, a test sample may be added to the diagnostic test device 700 in any suitable manner, for example, by adding a fluid, such as an ELB solution and a test sample, into an empty sample preparation reservoir 712. The method next moves to a block 904, where the sample fluid from the sample preparation reservoir 712 is dispensed to the diagnostic test reservoir of the diagnostic test device 700. In some implementations, the diagnostic test reservoir may be the reaction chamber 204 of dual tubes 202. Optionally, in accordance with a block 906, lyophilized reagents 802 within the diagnostic test reservoir may be rehydrated, for example by the sample fluid dispensed to the diagnostic test reservoir at the block 904. Optionally, in accordance with a block 908, heat may be applied to the diagnostic test reservoir. The method next moves to a block 910 where an assay, such as an amplification reaction, is performed. For example, heat may be applied to the diagnostic test reservoir to perform an amplification reaction in the sample fluid in the diagnostic test reservoir. It will be understood that other assays, that do not require heat, can be suitably implemented in methods of the present disclosure. Advantageously, the volume of sample fluid in the diagnostic test reservoir available to an assay performed in the diagnostic test reservoir including an anti-fogging agent according to the present disclosure is optimized, because beading or fogging of the fluid sample on interior surfaces of the diagnostic test reservoir is minimized or substantially eliminated. The method next moves to an optional block 912, where a change in the fluorescence of the sample fluid within the diagnostic test reservoir, indicative of a test result, is detected. As an illustrative example, fluorescent signals may increase in intensity as an amplification reaction proceeds.

[0076] The method ends at a block 914, where a presence or absence of an analyte of interest is detected. In certain implementations, such detection may be, at least in part, dependent on a change in fluorescence signal detected at the block 912. A diagnostic test result provided at the block 914 in accordance with embodiments of the method 900 can have improved accuracy and specificity due to a larger quantity of analyte of interest being included in the assay in the diagnostic test reservoir.

Testing of Example Diagnostic Test Devices Implementing an Anti-Fogging Agent

[0077] Various potential plastic additives or plastic surface treatments or surface coatings were initially selected and evaluated for their ability to enhance delivery and collection of a solution in an example diagnostic test device. Diagnostic test devices described with reference to FIGs. 7A-7C were prepared. Plastic forming the dual tubes 202 was modified with candidate additives, treatments and coatings to evaluate efficacy of each modified plastic in preventing or reducing fogging or creation of droplets on the interior surfaces of the reaction chambers 204. The material modifications evaluated during this test included: addition of a parylene coating to alter the polypropylene surface polarity; plasma or corona treatment to increase the polypropylene surface wettability; dip coating with polytetrafluoroethylene (PTFE) to modify the polypropylene surface polarity; dip coating with polydimcthylsiloxanc (PDMS) to modify the polypropylene surface polarity; vacuum deposition of silicon dioxide (SiCh) to increase polypropylene surface wettability; treatment with Silmer® UR- 5050 (available from Siltech Corporation) to increase water repellancy of the polypropylene surface; and creating dual tubes from blended polypropylene with 5% (w/w) Atmer™ 7373 (available from Croda), an anti-fogging agent. Untreated polypropylene dual tubes were also included in the test as a control. The number and size of ELB solution droplets adhering to the interior surface of the dual tube 202 were evaluated and quantified for each of candidate material modifications.

[0078] FIG. 10A is a graph illustrating the performance of each candidate material modification and the control (untreated polypropylene). The graph illustrates a retained volume of ELB solution for each tube condition, with each data point corresponding to a solution dispense event using a diagnostic test device 700 described above with reference to FIGs. 7A-7C. A measured retained volume in pL is provided on the y-axis while the material modification is provided on the x-axis. During the test, an ELB solution including 2% weight/volume sodium dodecylsulfate solution (SDS) was dispensed by rapid nucleic acidbased diagnostic test devices into 30 separate dual tubes prepared with each candidate material modification. The volume of fluid at the bottom portion of the dual tubes was measured immediately after dispense to create Measurement 1. After this initial measurement, each dual tube was shaken or tapped to cause any droplets or fogging present on the interior surfaces of the dual tubes to settle to the bottom portion of the dual tubes. The volume of liquid at the bottom portion of the dual tubes was remeasured, to create Measurement 2. The retained volume in pL was calculated by subtracting Measurement 1 from Measurement 2. The retained volume is an estimate of the volume of liquid adhered high on the interior walls of the tubes, for example by beading and/or fogging on the surfaces above the bottom portion of the dual tubes. Treatments were then evaluated to determine how well they minimized retained volume, so as to maximize the proportion of liquid dispensed to the dual tubes that settles to the bottom of the tubes, where amplification and detection takes place.

[0079] As shown in FIG. 10A, the untreated polypropylene dual tubes control had a relatively large distribution of retained volumes. On average, the retained volumes of the untreated polypropylene dual tubes are also relatively large. This contrasts with the Atmer™ 7373 additive condition, which had a relatively narrow distribution of retained volumes as well as a relatively low average retained volume. For instance, a maximum retained volume of 1 Op L obtained from test devices with the Atmer™ 7373 modification was used to evaluate the relative distribution and size of retained volumes for all other surface modifications and the control. Further, dual tubes made with polypropylene having Atmer™ 7373 blended in at a 5% (w/w) concentration had the lowest size droplets retained on the dual tube walls of any of the tested conditions. Additionally, the size consistency of these droplets with the added Atmer™ 7373 was superior to the untreated polypropylene, as well as any other option evaluated.

[0080] FIG. 10B shows a process capability plot for the dual tubes formed of untreated polypropylene, while FIG. 10C shows the same report for the dual tubes formed of polypropylene blended with 5% Atmer™ 7373 additive. In FIGs. 10B-10C, the x-axis plots dispense volume (in pL) as measured during Measurement 1, while the y-axis plots frequency. A performance specification of 100 pL +/- 20 pL was used, indicated by the lower specification limit (LSL) and upper specification limit (USL) dashed lines. The Atmer™ 7373 anti-fogging additive achieved the performance specification of 100 +/- 20 pL dispense volume, whereas the untreated polypropylene dual tubes did not achieve this performance specification.

[0081] The test results demonstrated that the total volume of a sample solution transferred and dispensed to a specified location within a diagnostic test device can be advantageously increased by implementing Atmer™ 7373 additive as an anti-fogging agent in a portion of the device formed of plastic, such as but not limited to polypropylene.

[0082] Other tests established that reaction chamber surfaces including Atmer™ 7373 were compatible with amplification test assay chemistry. The amplification reaction was not substantially affected by presence of Atmer™ 7373 within the reaction chamber. Further, presence of Atmer™ 7373 did not substantially affect delivery of optical signals or transmission of light from fluorescent molecules involved in the amplification reaction to the optical detectors.

[0083] Embodiments of diagnostic test devices, systems, and method implementing an anti-fogging agent according to the present disclosure have been described with reference to example devices having plastic components that include an anti-fogging agent. It will be understood that the anti-fogging agent can be included in the plastic components in any suitable manner. Tn a non-limiting embodiment, a plastic material is blended with an anti-fogging agent and then formed into a plastic component, such as by injection molding.

[0084] In addition, it will be understood that embodiments of diagnostic test devices, systems, and methods implementing an anti-fogging agent according to the present disclosure have been described with reference to an anti-fogging agent having a hydrophobic portion and a hydrophilic portion, where the hydrophilic portion blooms to the surface of a plastic material, such that a water-based solution “sheets off’ the surface and reduces droplet adhesion on the surface. It will be understood, however, that embodiments of the present disclosure are not bound by any particular theory, and that an agent that increases the surface wettability, modifies the surface polarity, and/or increases water repellancy of a plastic surface, such as a surface formed of polypropylene or polyethylene, can be suitably implemented in diagnostic test devices, systems, and methods according to the present disclosure.

[0085] Further, embodiments of diagnostic test devices, systems, and methods of the present disclosure have been described with reference to an anti-fogging agent that is compounded into or blended with a host plastic material. It will be understood, however, that a plastic material of a diagnostic test device of the present disclosure may not use an antifogging agent and may instead be coated or treated to prevent or reduce droplet formation or fogging on a surface of the plastic material. In one non-limiting embodiment, a coating or treatment is adhered to a surface of a plastic material. The coating or treatment may be adhered using a chemical or mechanical process. In another non-limiting embodiment, a coating or treatment is applied in a film or layer to a surface of the plastic material.

[0086] Additionally, embodiments of the diagnostic test devices, systems, and methods of the present disclosure have been described with reference to a diagnostic test device including a cartridge body having a sample preparation reservoir, and a diagnostic test reservoir coupled to the cartridge body. It will be understood that the present disclosure is not limited to diagnostic test devices including a diagnostic test reservoir coupled to a cartridge body. For example, in one non-limiting embodiment, the diagnostic test reservoir incudes a unitary structure including a sample preparation reservoir and a diagnostic test reservoir, the diagnostic test reservoir configured to receive a fluid from the sample preparation reservoir. The diagnostic test reservoir includes a plastic and an anti-fogging agent configured to increase the surface wettability of the plastic. Tn this example, movement of fluid that is dispensed to the diagnostic test reservoir from the sample preparation reservoir is influenced by the anti-fogging agent to increase a quantity of analyte of interest available to an assay performed in the diagnostic test device.

Terminology

[0087] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art. The use of the term “including” as well as other forms, such as “include,” “includes,” and “included,” is not limiting. The use of the term “having” as well as other forms, such as “have,” “has,” and “had,” is not limiting. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. That is, the above terms are to be interpreted synonymously with the phrases “having at least” or “including at least.” For example, when used in the context of a process, the term “comprising” means that the process includes at least the recited steps, but may include additional steps. When used in the context of a device, the term “comprising” means that the device includes at least the recited features or components, but may also include additional features or components. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Further, the term “each,” as used herein, in addition to having its ordinary meaning, can mean any subset of a set of elements to which the term “each” is applied.

[0088] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, or steps. Thus, such conditional language is not generally intended to imply that features, elements, or steps are in any way required for one or more embodiments.

[0089] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z. [0090] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount.

[0091] The term “and/or” as used herein has its broadest least limiting meaning which is the disclosure includes A alone, B alone, both A and B together, or A or B alternatively, but does not require both A and B or require one of A or one of B . As used herein, the phrase “at least one of’ A, B, “and” C should be construed to mean a logical A or B or C, using a non-exclusive logical or.

[0092] Conditional language used herein, such as, among others, “can,” “could,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain, certain features, elements and/or steps are optional. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.

[0093] Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication.

[0094] Some or all of the methods and tasks described herein may be performed and fully automated by a computer system. A diagnostic test system according to the present disclosure can include a computer system that may, in some cases, include multiple distinct computers or computing devices (for example, physical servers, workstations, storage arrays, cloud computing resources, etc.) that communicate and interoperate over a network to perform the described functions. Each such computing device typically includes a processor (or 1 multiple processors) that executes program instructions or modules stored in a memory or other non-transitory computer-readable storage medium or device (for example, solid state storage devices, disk drives, etc.). The various functions disclosed herein may be embodied in such program instructions, and/or may be implemented in application-specific circuitry (for example, ASICs or FPGAs) of the computer system. Where the computer system includes multiple computing devices, these devices may, but need not, be co-located. The results of the disclosed methods and tasks may be persistently stored by transforming physical storage devices, such as solid-state memory chips and/or magnetic disks, into a different state. The computer system may be a cloud-based computing system whose processing resources are shared by multiple distinct business entities or other users.

[0095] While the above detailed description has shown, described, and pointed out novel features, it can be understood that various omissions, substitutions, and changes in the form and details of the devices, systems, and methods can be made without departing from the spirit of the present disclosure. As can be recognized, certain portions of the description herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some features can be used or practiced separately from others. Consequently, it is not intended that the present disclosure be limited to the specific embodiments disclosed herein, but that it covers all modifications and alternatives coming within the true scope and spirit of the present disclosure as embodied in the attached claims.

Claims

WHAT IS CLAIMED IS:

1. A diagnostic test device comprising: a cartridge body comprising a sample preparation reservoir; and a diagnostic test reservoir coupled to the cartridge body, the diagnostic test reservoir comprising at least one chamber configured to receive a fluid from the sample preparation reservoir, wherein the at least one chamber comprises a plastic and an antifogging agent, the anti-fogging agent configured to increase the surface wettability of the plastic.

2. The diagnostic test device of claim 1, wherein the anti-fogging agent is configured to inhibit droplets of the fluid from adhering to interior surfaces of the at least one chamber when the fluid is dispensed into the at least one chamber from the sample preparation reservoir.

3. The diagnostic test device of claim 1, wherein the anti-fogging agent is blended with the plastic.

4. The diagnostic test device of claim 1, wherein the anti-fogging agent comprises a hydrophobic portion and a hydrophilic portion.

5. The diagnostic test device of claim 1, wherein the at least one chamber is formed by injection-molding the plastic compounded with the anti-fogging agent.

6. The diagnostic test device of claim 1, comprising a lyophilized reagent within the at least one chamber.

7. The diagnostic test device of claim 6, wherein the lyophilized reagent comprises nucleic acid amplification primers.

8. The diagnostic test device of claim 6, wherein the lyophilized reagent comprises a nucleic acid amplification detection probe.

9. The diagnostic test device of claim 1, further comprising a seal between the sample preparation reservoir and the at least one chamber, the seal configured to prevent movement of the fluid between the sample preparation reservoir and the at least one chamber.

10. The diagnostic test device of claim 9, further comprising a dispensing mechanism configured to break the seal to allow movement of the fluid from the sample preparation reservoir into the at least one chamber.

1 1 . The diagnostic test device of claim 1 , wherein the diagnostic test device includes the fluid, and wherein the fluid comprises a water-based buffer solution.

12. The diagnostic test device of claim 11, wherein the water-based buffer solution comprises at least one of: an RBCC, a GRBS, and SDS.

13. The diagnostic test device of claim 11 , wherein the sample preparation reservoir is configured to receive a test sample.

14. The diagnostic test device of claim 13, wherein the sample preparation reservoir is configured to receive a swab comprising the test sample.

15. The diagnostic test device of claim 13, wherein at least a portion of the fluid and at least a portion of the test sample is configured to move from the sample preparation reservoir to the at least one chamber.

16. The diagnostic test device of claim 1, wherein the at least one chamber comprises two tubes.

17. The diagnostic test device of claim 1, wherein the plastic comprises polypropylene.

18. The diagnostic test device of any of the preceding claims, wherein the at least one chamber comprises a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and wherein the anti-fogging agent is configured to increase a volume of the fluid that is collected in the second end.

19. A method of performing a diagnostic test using a diagnostic test device, the diagnostic test device comprising a sample preparation reservoir and a diagnostic test reservoir, the method comprising: dispensing a fluid from the sample preparation reservoir into at least one chamber of the diagnostic test reservoir, wherein the at least one chamber comprises a plastic and an anti-fogging agent, the anti-fogging agent configured to increase the surface wettability of the plastic; performing an amplification reaction in the at least one chamber; and detecting the presence or absence of an analyte of interest in the at least one chamber.

20. The method of claim 19, further comprising adding a test sample to the fluid in the sample preparation reservoir before dispensing the fluid into the at least one chamber.

21. The method of claim 19, further comprising rehydrating a lyophilized reagent in the at least one chamber with the fluid dispensed from the sample preparation reservoir.

22. The method of claim 19, wherein performing an amplification reaction comprises applying heat to the at least one chamber.

23. The method of claim 19, wherein detecting the presence or absence of the analyte of interest comprises detecting changes in fluorescence indicative of a test result.

24. The method of claim 19, wherein the plastic comprises polypropylene.

25. The method of any of claims 19-24, wherein the at least one chamber comprises a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and wherein the anti-fogging agent is configured to increase a volume of the fluid that is collected in the second end.

26. A diagnostic test device comprising: a cartridge body comprising a sample preparation reservoir; and a diagnostic test reservoir coupled to the cartridge body, the diagnostic test reservoir comprising at least one chamber comprising a plastic and configured to receive a fluid from a sample preparation reservoir, wherein an interior surface of the at least one chamber is treated with an agent configured to inhibit droplets of the fluid from adhering to the interior surface of the at least one chamber.

27. The diagnostic test device of claim 26, wherein the agent is configured to modify surface polarity of the interior surface of the at least one chamber.

28. The diagnostic test device of claim 26, wherein the agent is configured to increase surface wettability of the interior surface of the at least one chamber.

29. The diagnostic test device of claim 26, wherein the agent comprises parylene, polytetrafluoroethylene (PTFE), polydimethylsiloxane (PDMS), or silicon dioxide (SiCh).

30. The diagnostic test device of claim 26, further comprising a lyophilized reagent within the at least one chamber.

31. The diagnostic test device of claim 30, wherein the lyophilized reagent comprises nucleic acid amplification primers and a nucleic acid amplification detection probe.

32. The diagnostic test device of claim 26, further comprising a seal between the sample preparation reservoir and the at least one chamber, the seal configured to prevent movement of the fluid between the sample preparation reservoir and the at least one chamber.

33. The diagnostic test device of claim 32, further comprising a dispensing mechanism configured to break the seal to allow movement of the fluid from the sample preparation reservoir into the at least one chamber.

34. The diagnostic test device of claim 26, wherein the plastic comprises polypropylene.

35. The diagnostic test device of any of claims 26-34, wherein the at least one chamber comprises a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and wherein the agent is configured to increase a volume of the fluid that is collected in the second end.

36. A method of performing a diagnostic test using a diagnostic test device, the diagnostic test device comprising a sample preparation reservoir and a diagnostic test reservoir, the method comprising: dispensing a fluid from the sample preparation reservoir into at least one chamber of the diagnostic test reservoir, wherein an interior surface of the at least one chamber is treated with an agent configured to inhibit droplets of the fluid from adhering to the interior surface of the at least one chamber; performing an amplification reaction in the at least one chamber; and detecting the presence or absence of an analyte of interest in the at least one chamber.

37. The method of claim 36, further comprising adding a test sample to the fluid in the sample preparation reservoir before dispensing the fluid into the at least one chamber.

38. The method of claim 36, further comprising rehydrating a lyophilized reagent in the at least one chamber with the fluid dispensed from the sample preparation reservoir.

39. The method of claim 36, wherein performing an amplification reaction comprises applying heat to the at least one chamber.

40. The method of claim 36, wherein detecting the presence or absence of the analyte of interest comprises detecting changes in fluorescence indicative of a test result.

41. The method of claim 36, wherein the plastic comprises polypropylene.

42. The method of any of claims 36-41 , wherein the at least one chamber comprises a first end coupled to the sample preparation reservoir and a second end configured to collect the fluid dispensed from the sample preparation reservoir, and wherein the agent is configured to increase a volume of the fluid that is collected in the second end.