Lateral flow assay with sample qualification line

Abstract

The immunoassay devices, systems, and methods described herein measure the presence of an analyte of interest in a sample, as well as the presence of a sample suitability marker in the sample. The sample suitability marker allows for the assessment of the quality, quantity, and composition of the sample. In one embodiment, the sample suitability marker in the sample comprises human albumin. In another embodiment, the sample suitability marker in the sample comprises lactotransferrin. The immunoassay devices, systems, and methods can distinguish between samples that do not contain the analyte of interest and samples that are of insufficient suitability to obtain accurate results. The immunoassay devices, systems, and methods described herein can be implemented as part of a clinical system, a laboratory system, or a home testing system.

Description

[Technical field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Application No. 63 / 149,321, filed February 14, 2021, the entire disclosure of which is incorporated herein by reference.

[0002] (Technical field) The present disclosure relates generally to immunoassay devices, systems, and methods. More specifically, the present disclosure relates to immunoassay test strips that include a reagent test decision line used to indicate sample suitability such that a negative test result due to the absence of an analyte of interest in the sample is distinguishable from a negative test result due to insufficient sample quality, quantity, or composition. [Background technology]

[0003] The immunoassay systems described herein allow for reliable, inexpensive, portable, rapid, and simple diagnostic testing. Immunoassays rapidly and accurately detect the presence or absence of an analyte of interest in a sample, and in some cases can quantitate the analyte. Advantageously, most immunoassays are minimally invasive and are used as point-of-care testing systems. Immunoassays have been developed to detect a wide variety of medical or environmental analytes. Summary of the Invention [Problem to be solved by the invention]

[0004] However, immunoassays suffer from a number of drawbacks, including false negatives, inaccurately low results, and poor resolution when the analyte of interest is present in high concentrations in the sample. [Means for solving the problem]

[0005] Disclosed herein is an immunoassay test strip comprising a flow path configured to receive a sample, a sample receiving zone coupled to the flow path, at least one sample qualification line, and at least one analyte capture line. Although several embodiments of the present disclosure are described in relation to an immunoassay test strip, it should be understood that, according to the present disclosure, the use of sample qualification markers to indicate the suitability of a sample can also be implemented in immunoassays that do not use a test strip format, including, but not limited to, assays performed using plate-based or well-plate assays, Luminex assays, ELISA assays, bead-based assays, and microarray assays. In some embodiments, the sample comprises at least one sample qualification marker, and at least one sample qualification marker in the sample comprises human albumin, and at least one sample qualification line comprises an anti-HSA antibody. In some embodiments, the sample comprises at least one sample qualification marker, and at least one sample qualification marker in the sample comprises lactotransferrin, and at least one sample qualification line comprises an anti-lactotransferrin antibody. In some embodiments, the presence and abundance of at least one sample suitability marker in a sample depends on the quantity, quality, and / or composition of the sample. In some embodiments, the sample further comprises at least one analyte of interest. In some embodiments, the presence and abundance of at least one sample suitability marker in a sample depends on the disease state of the donor. In some embodiments, the sample is selected from the group consisting of a nasal sample, a mucus sample, a blood sample, a plasma sample, a urine sample, a sweat sample, or a saliva sample taken from the donor. In some embodiments, the at least one analyte of interest in the sample comprises a marker for an infectious disease. In some embodiments, the at least one analyte of interest in the sample comprises a viral marker. In some embodiments, the at least one analyte of interest in the sample comprises a marker for SARS-CoV-2. In some embodiments, the at least one analyte of interest in the sample comprises a marker for influenza. In some embodiments, the at least one analyte of interest in the sample comprises a marker for influenza A virus.In some embodiments, at least one analyte of interest in the sample includes a marker for influenza B virus. In some embodiments, at least one analyte of interest in the sample includes a marker for influenza and a marker for SARS-CoV-2. In some embodiments, at least one analyte of interest in the sample includes a bacterial marker. In some embodiments, the sample provider is a mammal. In some embodiments, the sample provider is a human. In some embodiments, the test strip is used as part of a direct immunoassay. In some embodiments, the test strip is used as part of an indirect immunoassay. In some embodiments, the test strip is used as part of a sandwich immunoassay. In some embodiments, the test strip is used as part of a competitive immunoassay. In some embodiments, the test strip is used as part of a lateral flow assay. In some embodiments, the test strip is used in a BD Veritor™ system. In some embodiments, the test strip is used in a BD Veritor™ at-home COVID-19 test. In some embodiments, the test strip further comprises a negative control line. In some embodiments, the test strip further comprises a positive control line. In some embodiments, the positive control line is positioned on the test strip between at least one analyte capture line and at least one sample qualification line, between at least one analyte capture line and a negative control line, or between at least one sample qualification line and a negative control line. In some embodiments, the positive control line verifies the integrity of the immunoassay, proper reagent function, and ensures a correct testing procedure. In some embodiments, the negative control line verifies the integrity of the immunoassay, proper reagent function, and ensures a correct testing procedure. In some embodiments, the sample is unlabeled when it enters the flow path. In some embodiments, the sample is labeled when it enters the flow path.

[0006] Some aspects of the present disclosure relate to methods for assessing suitability of a sample using an immunoassay test strip comprising a flow path configured to receive a sample, a sample receiving zone coupled to the flow path, at least one sample qualification line, and at least one analyte capture line, the method including applying the sample to the immunoassay test strip, flowing the sample within the flow path to the sample receiving zone, monitoring for the presence of at least one analyte of interest in the sample by immunoassay performed at the at least one analyte capture line, and monitoring for the presence of at least one sample qualification marker in the sample by immunoassay performed at the at least one sample qualification line, wherein detection of the at least one sample qualification marker is used as an indication of the quantity, quality, and / or composition of the sample. Although embodiments of the present disclosure are described in relation to a method for assessing sample suitability using immunoassay test strips, it is understood that, according to the present disclosure, the use of sample suitability markers to indicate sample suitability can also be performed in immunoassays that do not use a test strip format, including, but not limited to, assays performed using plate-based or well-plate assays, Luminex assays, ELISA assays, bead-based assays, and microarray assays. In some embodiments, the sample comprises at least one sample suitability marker, and at least one sample suitability marker in the sample comprises human albumin, and at least one sample suitability line comprises an anti-HSA antibody. In some embodiments, the sample comprises at least one sample suitability marker, and at least one sample suitability marker in the sample comprises lactotransferrin, and at least one sample suitability line comprises an anti-lactotransferrin antibody. In some embodiments, the sample further comprises at least one analyte of interest. In some embodiments, the presence and abundance of at least one sample suitability marker in the sample depends on the disease state of the donor. In some embodiments, the sample is selected from the group consisting of a nasal sample, a mucus sample, a blood sample, a plasma sample, a urine sample, a sweat sample, or a saliva sample collected from a donor, hi some embodiments, at least one analyte of interest in the sample comprises a marker for an infectious disease.In some embodiments, at least one analyte of interest in the sample comprises a viral marker. In some embodiments, at least one analyte of interest in the sample comprises a marker for SARS-CoV-2. In some embodiments, at least one analyte of interest in the sample comprises a marker for influenza. In some embodiments, at least one analyte of interest in the sample comprises a marker for influenza A virus. In some embodiments, at least one analyte of interest in the sample comprises a marker for influenza B virus. In some embodiments, at least one analyte of interest in the sample comprises a marker for influenza and a marker for SARS-CoV-2. In some embodiments, at least one analyte of interest in the sample comprises a bacterial marker. In some embodiments, the donor of the sample is a mammal. In some embodiments, the donor of the sample is a human. In some embodiments, the immunoassay used to monitor for the presence of at least one analyte of interest is a direct immunoassay. In some embodiments, the immunoassay used to monitor for the presence of at least one sample suitability marker is a direct immunoassay. In some embodiments, the immunoassay used to monitor for the presence of at least one analyte of interest is an indirect immunoassay. In some embodiments, the immunoassay used to monitor the presence of at least one sample suitability marker is an indirect immunoassay. In some embodiments, the immunoassay used to monitor the presence of at least one analyte of interest is a sandwich immunoassay. In some embodiments, the immunoassay used to monitor the presence of at least one sample suitability marker is a sandwich immunoassay. In some embodiments, the immunoassay used to monitor the presence of at least one analyte of interest is a competitive immunoassay. In some embodiments, the immunoassay used to monitor the presence of at least one sample suitability marker is a competitive immunoassay. In some embodiments, the immunoassay is a lateral flow assay.In some embodiments, the immunoassay is performed using a BD Veritor™ system. In some embodiments, the immunoassay is performed using a BD Veritor™ at-home COVID-19 test. In some embodiments, the immunoassay test strip further comprises a negative control line. In some embodiments, the immunoassay test strip further comprises a positive control line. In some embodiments, the positive control line is positioned on the test strip between at least one analyte capture line and at least one sample qualification line, between at least one analyte capture line and a negative control line, or between at least one sample qualification line and a negative control line. In some embodiments, the positive control line verifies the integrity of the immunoassay, proper reagent function, and ensures correct testing procedure. In some embodiments, the negative control line verifies the integrity of the immunoassay, proper reagent function, and ensures correct testing procedure. In some embodiments, the sample is unlabeled when entering the flow path. In some embodiments, the sample is labeled when entering the flow path. In some embodiments, if the presence of at least one sample suitability marker is not detected, the method further comprises displaying an indication that the sample is of insufficient quality. In some embodiments, if the presence of at least one sample suitability marker is detected, the method further comprises displaying an indication that the sample is of sufficient quality. In some embodiments, if the presence of at least one sample suitability marker is detected at a high concentration, the method further comprises displaying an indication that the sample is present at a high concentration. In some embodiments, if the presence of at least one sample suitability marker is detected at a low concentration, the method further comprises displaying an indication that the sample is present at a low concentration. In some embodiments, if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is not detected, the method further comprises displaying an indication that at least one analyte of interest is not detected. In some embodiments, if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is detected, the method further comprises an indication that the analyte of interest is present.In some embodiments, if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is detected at a high concentration, the method further comprises displaying an indication that the analyte of interest is present at a high concentration. In some embodiments, if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is detected at a low concentration, the method further comprises displaying an indication that the analyte of interest is present at a low concentration. If the presence of at least one sample suitability marker is detected and the presence of a first analyte of the at least one analyte of interest is detected and the presence of a second analyte of the at least one analyte of interest is not detected, the method further comprises displaying an indication that the first analyte of the at least one analyte of interest is present and the second analyte of the at least one analyte of interest is not detected. In some embodiments, monitoring the presence of at least one sample suitability marker in the sample comprises visually observing at least one sample suitability line for the presence of an optical signal. In some embodiments, monitoring the presence of at least one analyte of interest in the sample comprises visually observing at least one analyte capture line for the presence of an optical signal. In some embodiments, monitoring the presence of at least one sample qualification marker in the sample comprises acquiring an image of at least one sample qualification line, hi some embodiments, monitoring the presence of at least one analyte of interest in the sample comprises acquiring an image of at least one analyte capture line.

[0007] Some aspects of the present disclosure relate to a test kit. The test kit may include any of the immunoassay test strips described above and computer readable code identifying a software application configured to analyze an image of the immunoassay test strip and determine a test result based at least in part on at least one sample qualification line. In some embodiments, the test result determined by the software application is an invalid test result based at least in part on the software application determining that an intensity of an optical signal from at least one sample qualification line is below a preset threshold. In some embodiments, the test result determined by the software application is a valid test result based at least in part on the software application determining that an intensity of an optical signal from at least one sample qualification line is above a preset threshold.

[0008] Several embodiments of the disclosure presented herein are described using the following numbered alternatives. Alternative form 1. a flow path configured to receive a sample; a sample receiving zone coupled to the flow path; At least one sample fitness line; at least one analyte capture line; 1. An immunoassay test strip comprising: Alternative form 2. 2. The immunoassay test strip of alternative 1, wherein the sample comprises at least one sample suitability marker, wherein the at least one sample suitability marker in the sample comprises human albumin, and wherein the at least one sample suitability line further comprises an anti-HSA antibody. Alternative form 3. 2. The immunoassay test strip of alternative 1, wherein the sample comprises at least one sample suitability marker, wherein the at least one sample suitability marker in the sample comprises lactotransferrin, and wherein the at least one sample suitability line comprises an anti-lactotransferrin antibody. Alternative form 4. An immunoassay test strip according to any of alternatives 2 to 3, wherein the presence and abundance of the at least one sample suitability marker in the sample is dependent on the quantity, quality, and / or composition of the sample. Alternative form 5. An immunoassay test strip according to any of alternatives 1 to 4, wherein the sample comprises at least one analyte of interest. Alternative Form 6. The immunoassay test strip of alternative 5, wherein the presence and abundance of the at least one sample suitability marker in the sample is dependent on a disease state of the donor. Alternative form 7. 7. The immunoassay test strip of any one of alternatives 1 to 6, wherein the sample is selected from the group consisting of a nasal sample, a mucus sample, a blood sample, a plasma sample, a urine sample, a sweat sample, or a saliva sample collected from a donor. Alternative Form 8. An immunoassay test strip according to any of alternatives 1 to 7, wherein at least one analyte of interest in the sample comprises a marker for an infectious disease. Alternative form 9. The immunoassay test strip of alternative 8, wherein the at least one analyte of interest in the sample comprises a viral marker. Alternative form 10. 10. The immunoassay test strip of any of alternatives 8 to 9, wherein at least one analyte of interest in the sample comprises a marker for SARS-CoV-2. Alternative form 11. 11. An immunoassay test strip according to any of alternatives 8 to 10, wherein at least one analyte of interest in the sample comprises a marker for influenza. Alternative form 12. 12. The immunoassay test strip of alternative 11, wherein at least one analyte of interest in the sample comprises a marker for influenza A virus. Alternative form 13. 12. The immunoassay test strip of alternative 11, wherein at least one analyte of interest in the sample comprises a marker for influenza B virus. Alternative form 14. 12. The immunoassay test strip of any of alternatives 8 to 11, wherein at least one analyte of interest in the sample comprises a marker for influenza and a marker for SARS-CoV-2. Alternative form 15. The immunoassay test strip of alternative 8, wherein at least one analyte of interest in the sample comprises a bacterial marker. Alternative form 16. 13. The immunoassay test strip of any one of alternatives 1 to 12, wherein the sample provider is a mammal. Alternative form 17. 14. The immunoassay test strip of any one of alternatives 1 to 13, wherein the sample provider is a human. Alternative form 18. 18. The immunoassay test strip of any of alternatives 1 to 17, wherein the test strip is used as part of a direct immunoassay. Alternative form 19. 18. An immunoassay test strip according to any of alternatives 1 to 17, wherein the test strip is used as part of an indirect immunoassay. Alternative form 20. 18. The immunoassay test strip of any of alternatives 1 to 17, wherein the test strip is used as part of a sandwich immunoassay. Alternative form 21. 18. An immunoassay test strip according to any of alternatives 1 to 17, wherein the test strip is used as part of a competitive immunoassay. Alternative form 22. 22. The immunoassay test strip of any of alternatives 1 to 21, wherein the test strip is used as part of a lateral flow assay. Alternative form 23. 23. An immunoassay test strip according to any of alternatives 1 to 22, wherein the test strip is for use with the BD Veritor™ system. Alternative form 24. 24. The immunoassay test strip of any of alternatives 1 to 23, wherein the test strip is used in the BD Veritor™ at-home COVID-19 test. Alternative form 25. 25. The immunoassay test strip of any one of alternatives 1 to 24, wherein the test strip further comprises a positive control line and / or a negative control line. Alternative form 26. An immunoassay test strip as described in alternative 25, wherein the test strip includes a positive control line positioned on the test strip between at least one analyte capture line and at least one sample qualification line, between at least one analyte capture line and a negative control line, or between at least one sample qualification line and a negative control line. Alternative form 27. 27. The immunoassay test strip of alternative 26, wherein the positive control line verifies immunoassay integrity, proper reagent function, and ensures correct testing procedure. Alternative form 28. 26. The immunoassay test strip of alternative 25, wherein the test strip comprises a negative control line, the negative control line verifying immunoassay integrity, proper reagent functioning, and ensuring correct testing procedure. Alternative form29. 29. An immunoassay test strip of any of alternatives 1 to 28, wherein the sample is unlabeled upon entry into the flow path. Alternative form 30. 29. The immunoassay test strip of any one of alternatives 1 to 28, wherein the sample is labeled upon placement in the flow path. Alternative form 31. 1. A method for assessing sample suitability using an immunoassay test strip comprising a flow path configured to receive a sample, a sample receiving zone coupled to the flow path, at least one sample suitability line, and at least one analyte capture line, comprising: applying a sample to an immunoassay test strip; flowing the sample through a flow path to a sample receiving zone; monitoring the presence of at least one analyte of interest in the sample by an immunoassay performed at at least one analyte capture line; monitoring the presence of at least one sample suitability marker in the sample by an immunoassay performed at at least one sample suitability line; Including, A method in which detection of at least one sample integrity marker is used as an indication of the quantity, quality, and / or composition of the sample. Alternative Form 32. The method of alternative 31, wherein the sample comprises at least one sample suitability marker, wherein the at least one sample suitability marker in the sample comprises human albumin, and wherein the at least one sample suitability marker in the sample comprises an anti-HSA antibody. Alternative form 33. The method of alternative 31, wherein the sample comprises at least one sample suitability marker, wherein the at least one sample suitability marker in the sample comprises lactotransferrin, and wherein the at least one sample suitability marker comprises an anti-lactotransferrin antibody. Alternative form34. 34. The method of any of alternatives 31 to 33, wherein the sample comprises at least one analyte of interest. Alternative Form 35. The method of alternative 34, wherein the presence and abundance of at least one sample suitability marker in the sample is dependent on the disease state of the donor. Alternative Form 36. 36. The method of any of alternatives 31 to 35, wherein the sample is selected from the group consisting of a nasal sample, a mucus sample, a blood sample, a plasma sample, a urine sample, a sweat sample, or a saliva sample taken from a donor. Alternative Form 37. 37. The method of any of alternatives 31 to 36, wherein at least one analyte of interest in the sample comprises a marker for an infectious disease. Alternative form38. The method of alternative 37, wherein at least one analyte of interest in the sample comprises a viral marker. Alternative form39. 39. The method of any of alternatives 37 to 38, wherein at least one analyte of interest in the sample comprises a marker for SARS-CoV-2. Alternative form40. 40. The method of any of alternatives 37 to 39, wherein at least one analyte of interest in the sample comprises a marker for influenza. Alternative Form 41. The method of alternative 40, wherein at least one analyte of interest in the sample comprises a marker for influenza A virus. Alternative Form 42. The method of alternative 40, wherein at least one analyte of interest in the sample comprises a marker for influenza B virus. Alternative Form 43. 41. The method of any of alternatives 37 to 40, wherein at least one analyte of interest in the sample comprises a marker for influenza and a marker for SARS-CoV-2. Alternative form44. The method of alternative 37, wherein at least one analyte of interest in the sample comprises a bacterial marker. Alternative Form 45. The method of any one of alternatives 31 to 44, wherein the donor of the sample is a mammal. Alternative form46. The method of any of alternatives 31 to 45, wherein the sample provider is a human. Alternative form47. 47. The method of any of alternatives 31 to 46, wherein the immunoassay used to monitor the presence of the at least one analyte of interest is a direct immunoassay. Alternative form48. 48. The method of any of alternatives 31-47, wherein the immunoassay used to monitor the presence of at least one sample suitability marker is a direct immunoassay. Alternative form49. The method of any of alternatives 31 to 46 and alternative 48, wherein the immunoassay used to monitor the presence of the at least one analyte of interest is an indirect immunoassay. Alternative form50. The method of any of alternatives 31 to 47 and alternative 49, wherein the immunoassay used to monitor the presence of at least one sample suitability marker is an indirect immunoassay. Alternative form51. The method of any of alternatives 31 to 46, alternative 48, and alternative 50, wherein the immunoassay used to monitor for the presence of at least one analyte of interest is a sandwich immunoassay. Alternative form52. The method of any of alternatives 31 to 47, alternative 49, and alternative 51, wherein the immunoassay used to monitor the presence of at least one sample suitability marker is a sandwich immunoassay. Alternative form53. The method of any of alternatives 31 to 46, alternative 48, alternative 50, and alternative 52, wherein the immunoassay used to monitor the presence of at least one analyte of interest is a competitive immunoassay. Alternative form54. The method of any of alternatives 31 to 47, alternative 49, alternative 51, and alternative 53, wherein the immunoassay used to monitor the presence of at least one sample suitability marker is a competitive immunoassay. Alternative form55. 55. The method of any of alternatives 31 to 54, wherein the immunoassay is a lateral flow assay. Alternative form56. The method of any of alternatives 31 to 54, wherein the immunoassay is performed using a BD Veritor™ system. Alternative form57. The method of any of alternatives 31 to 56, wherein the immunoassay is performed using the BD Veritor™ at-home COVID-19 test. Alternative form58. 58. The method of any one of alternatives 31 to 57, wherein the immunoassay test strip further comprises a positive control line and / or a negative control line. Alternative form59. The method of alternative 58, wherein the test strip comprises a positive control line, the positive control line being positioned on the test strip between at least one analyte capture line and at least one sample qualification line, between at least one analyte capture line and a negative control line, or between at least one sample qualification line and a negative control line. Alternative form60. The method according to alternative 59, wherein the positive control line verifies the integrity of the immunoassay, proper reagent function and ensures correct testing procedures. Alternative form 61. 59. The immunoassay test strip of alternative 58, wherein the test strip comprises a negative control line, the negative control line verifying immunoassay integrity, proper reagent functioning, and ensuring correct testing procedure. Alternative Form 62. 62. The method of any of alternatives 31 to 61, wherein the sample is unlabeled upon entering the flow path. Alternative Form 63. 62. The method of any of alternatives 31 to 61, wherein the sample is labeled upon entering the flow path. Alternative Form 64. 64. The method of any of alternatives 31 to 63, wherein if the presence of at least one sample suitability marker is not detected, the method further comprises displaying an indication that the sample is of insufficient quality. Alternative Form 65. 64. The method of any of alternatives 31 to 63, wherein if the presence of at least one sample suitability marker is detected, the method further comprises displaying an indication that the sample is of sufficient quality. Alternative Form 66. The method of alternative 65, wherein if the presence of at least one sample suitability marker is detected in a high concentration, the method further comprises displaying an indication that the sample is present in a high concentration. Alternative Form 67. The method of alternative 65, wherein if the presence of at least one sample suitability marker is detected at a low concentration, the method further comprises displaying an indication that the sample is present at a low concentration. Alternative Form 68. The method of any of alternatives 65 to 67, wherein if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is not detected, the method further comprises displaying an indication that the at least one analyte of interest was not detected. Alternative Form 69. The method of any of alternatives 65 to 67, wherein if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is detected, the method further comprises displaying an indication that the analyte of interest is present. Alternative form 70. The method of alternative 69, wherein if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is detected at a high concentration, the method further comprises displaying an indication that the analyte of interest is present at a high concentration. Alternative form 71. The method of alternative 69, wherein if the presence of at least one sample suitability marker is detected and the presence of at least one analyte of interest is detected at a low concentration, the method further comprises displaying an indication that the analyte of interest is present at a low concentration. Alternative form 72. 72. The method of any of alternatives 69 to 71, wherein if the presence of the at least one sample suitability marker is detected, the presence of the first one of the at least one analyte of interest is detected, and the presence of the second one of the at least one analyte of interest is not detected, the method further comprises displaying an indication that the first one of the at least one analyte of interest is present and the second one of the at least one analyte of interest is not detected. Alternative form 73. The method of any of alternatives 31 to 72, wherein monitoring the presence of at least one sample suitability marker in the sample comprises visually observing at least one sample suitability line for the presence of an optical signal. Alternative form 74. The method of any one of alternatives 31 to 73, wherein monitoring the presence of at least one analyte of interest in the sample comprises visually observing at least one analyte capture line for the presence of an optical signal. Alternative form 75. 73. The method of any of alternatives 31 to 72, wherein monitoring the presence of at least one sample suitability marker in the sample comprises obtaining an image of at least one sample suitability line. Alternative form 76. 73. The method of any of alternatives 31 to 72, wherein monitoring the presence of at least one analyte of interest in the sample comprises acquiring an image of at least one analyte capture line. Alternative form 77. A test kit comprising an immunoassay test strip of any one of alternatives 1 to 30 and computer readable code identifying a software application configured to analyze an image of the immunoassay test strip to determine a test result based at least in part on at least one sample qualification line. Alternative form 78. A test kit as described in alternative form 77, wherein the test result determined by the software application is an invalid test result based at least in part on the software application determining that the intensity of an optical signal from at least one sample qualification line is below a predetermined threshold. Alternative form 79. A test kit as described in alternative form 77, wherein the test result determined by the software application is a valid test result based at least in part on the software application determining that the intensity of an optical signal from at least one sample suitability line exceeds a predetermined threshold. [Brief description of the drawings]

[0009] [Figure 1]1 shows an exemplary immunoassay test strip according to the present disclosure, where L5 is the sample qualification line, L4 is the positive control line (PC), L3 is the blank line, L2 is the analyte capture line for the SARS-Cov-2 marker, L1 is the negative control line (NC), and B2 is the background section. [Diagram 2] 1 shows a histogram of sample fitness line intensity distribution in AU for 369 fluid samples collected and analyzed using an exemplary immunoassay according to the present disclosure. [Diagram 3] 1 shows a histogram of sample fitness line intensity distribution in AU for samples collected and analyzed during a clinical trial using an exemplary immunoassay according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The development of high quality rapid diagnostic tests has enabled the deployment of laboratory quality diagnostic assays into environments where it has long been impossible to process samples and obtain results in real time, enabling better patient care. However, one step in the diagnostic process has long remained problematic: obtaining the proper sample to be tested. Inadequate quality samples will lead to inadequate quality diagnostic test results. The resulting need for skilled medical professionals to be involved in sample collection has generally remained an obstacle to widespread deployment of these rapid technologies in all possible testing sites.

[0011] For this reason, a need exists to enable less trained individuals, including individuals outside of a laboratory, to collect clinical samples that are useful for analysis. A classic example of such an implementation is the use of urinary creatinine to normalize measurements of other biomarkers, such as albumin, to address variability in urine output that affects the interpretation of the biomarker of interest.

[0012] The value of such an implementation is that analytical measurements obtained from a clinical sample can be judged with respect to properties such as the validity of the sample. For example, in testing for addictive substances, an individual being tested may be tempted to attempt to tamper with the analytical results using mechanisms such as adding water to alter the measurement of the diagnostic target. A sample validity test can detect such tampering and the resulting results can be judged as valid or invalid, as appropriate.

[0013] The COVID-19 pandemic has created a need for mechanisms to detect viral infections on an unprecedented scale. This detection is best accomplished by widespread infectious disease testing in settings that have long been unconnected to laboratory-quality diagnostic testing, and in some cases by individuals with no experience in collecting validated samples suitable for such testing. There is clearly a need to ensure the quality of sample collection in widely dispersed non-laboratory settings, including airports, long-term care facilities, schools, and even home environments.

[0014] Much like the need for sample validity biomarkers in urine, there is a need to identify and detect biomarkers in nasal-derived samples that can be combined with more common rapid antigen tests for pathogens such as SARS-CoV-2 to ensure high-quality samples are collected by non-laboratory individuals for evaluation in non-laboratory settings.

[0015] Embodiments of the present disclosure relate to systems and techniques suitable for detection of analytes of interest that may be present in biological or non-biological samples, such as fluids. Throughout this disclosure, exemplary systems, devices, and methods will be described in the context of collecting, testing, and detecting analytes, such as those suitable for diagnostic tests related to infectious diseases, although it should be understood that the techniques can be used to collect, test, and detect any particle, molecule, or analyte of interest.

[0016] definition Unless otherwise defined, all scientific and technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. All patents, applications, published applications, and other publications cited herein are incorporated herein by reference in their entirety unless otherwise stated. In the event that there are a plurality of definitions for terms used herein, those in this section prevail unless stated otherwise.

[0017] As used herein, the singular forms "a" and "an" may refer to one or to more than one referent.

[0018] As used herein, the terms "about," "approximately," or "approximately" have their ordinary meaning as understood by one of ordinary skill in the art, and thus indicate that a value includes the inherent variation of error in the method employed to determine the value or the variation that exists among multiple determinations.

[0019] Throughout this specification, unless the context dictates otherwise, "comprising" and variations thereof shall be understood to imply the inclusion of the described step or element or group thereof, but not the exclusion of any other step or element or group thereof. "Consisting of" is intended to be inclusive and limited to anything preceding the phrase. Thus, the phrase "consisting of" indicates that the recited elements are required or essential, and that no other elements may be present. "Consisting essentially of" is intended to include any elements recited in the "of" portion of the phrase, and limited to other elements that do not interfere with or contribute to the activities or acts set forth in this disclosure with respect to those recited elements. Thus, the phrase "consisting essentially of" indicates that the recited elements are required or essential, but that other elements are optional and may or may not be present depending on whether the other elements have a material effect on the activities or acts of the recited elements.

[0020] Dimensions and values ​​disclosed herein should not be understood to be strictly limited to the exact numerical values ​​recited. Instead, each such dimension, unless expressly stated otherwise, is intended to mean both the recited value and a functionally equivalent range around this value. For example, a dimension disclosed as "20 mm" is intended to mean "about 20 mm."

[0021] As used herein, the terms "function" and "functional" have their plain and ordinary meaning as understood in the context of this specification, meaning a biological function, an enzymatic function, or a therapeutic function.

[0022] The present disclosure relates to immunoassay devices, testing systems, and methods. As used herein, "analyte" generally refers to a substance to be detected. Analytes of interest can include any detectable substance, such as, but not limited to, antibodies, antigens, antigenic substances, ligands, proteins, incomplete antigens, sugars, lipids, nucleic acids, RNA, DNA, amplification products, hormones, small molecules, cytokines, immune cells, immune cell particles, immune cell surfaces, bacterial particles, bacterial surfaces, virus particles, virus surfaces, cell fragments, cell surfaces, and harmful or harmless drugs or pollutants, such as anti-tumor drugs used in cancer treatment. Analytes include, but are not limited to, toxins, organic compounds, peptides, microorganisms, amino acids, steroids, vitamins, drugs (including those administered for therapeutic purposes and those administered for illicit purposes), drug intermediates or by-products, and metabolites of any of these substances or antibodies thereto.Some specific examples of analytes include SARS-CoV-2 particles, influenza A particles, influenza B particles, ferritin, creatinine kinase MB (CK-MB), human chorionic gonadotropin (hCG), digoxin, phenytoin, phenobarbitol, carbamazepine, vancomycin, gentamicin, theophylline, valproic acid, quinidine, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, progesterone, C-reactive protein (CRP), lipocalin, IgE antibodies, cytokines, TNF-related apoptosis-inducing ligand (TRAIL), vitamin B2 microglobulin, interferon gamma-inducible protein 10 (IP-10), glycated hemoglobin (Gly), and glycated hemoglobin (Gly). Hb), cortisol, digitoxin, N-acetylprocainamide (NAPA), procainamide, anti-rubella antibodies such as rubella IgG and rubella IgM, anti-toxoplasma antibodies such as Toxoplasma IgG (ToxoIgG) and Toxoplasma IgM (ToxoIgM), testosterone, salicylate, acetaminophen, hepatitis B virus surface antigen (HBsAg), anti-hepatitis B core antigen anti-HBs (anti-HBsAg), anti-hepatitis B core antigen anti-HBs (anti-HBsAg), anti-hepatitis B core antigen anti-HBs (anti-HBsAg), anti-HBsAg, ... These include HIV types 1 and 2 (HIV1 and HIV2), human T-cell leukemia virus types 1 and 2 (HTLV), hepatitis B e antigen (HBeAg), anti-hepatitis B e antigen antibody (anti-HBe), influenza virus, thyroid stimulating hormone (TSH), thyroxine (T4), total triiodothyronine (total T3), free triiodothyronine (free T3), carcinoembryonic antigen (CEA), lipoproteins, cholesterol, and triglycerides, and alpha-fetoprotein (AFP).Addictive drugs and controlled substances include, but are not intended to be limited to, amphetamines, methamphetamines, barbiturates (e.g., amobarbital, secobarbital, pentobarbital, barbiturates, phenobarbital, and barbital), benzodiazepines such as librium and valium, cannabinoids such as hashish and marijuana, cocaine, fentanyl, LSD, methaqualone, opiates (e.g., heroin, morphine, codeine, hydromorphone, hydrocodone, methadone, oxycodone, oxymorphone, and opium), phencyclidine, and propoxyphene. Additional analytes may be included in the application of biological or environmental materials of interest. As used herein, the analyte of interest may be present in the sample based on the disease state of the sample provider.

[0023] Immunoassays As used herein, the term "immunoassay" has its plain and ordinary meaning as understood in the context of this specification, and refers to a biochemical test that measures the presence or concentration of one or more analytes in a solution through the use of an antibody or an antigen. Examples of immunoassays include radioimmunoassays, enumeration immunoassays, enzyme immunoassays, fluorescent immunoassays, and chemiluminescence immunoassays.

[0024] The presently disclosed embodiments relate to test strips for use in immunoassays and include a sample qualification line. Although the presently disclosed embodiments are described herein in relation to the use of these test strips for direct, indirect, sandwich, and competitive immunoassays, it should be understood that the test strips described herein can be used as components in any analyte detection assay. Furthermore, although the presently disclosed embodiments are described in relation to test strips, it should be understood that the present disclosure can be implemented in any suitable format, as described in more detail below.

[0025] As used herein, the term "direct immunoassay" has its ordinary meaning as understood by those of skill in the art, and thus refers to the direct measurement of an analyte of interest by a labeled antibody or antigen specific for the analyte. In some embodiments, the antibody or antigen is immobilized on a test strip, and the analyte of interest is contacted with the antibody or antigen in solution. In some embodiments, the analyte of interest is immobilized on a test strip, and the labeled antibody or antigen is contacted with the analyte in solution.

[0026] As used herein, the term "indirect immunoassay" has its ordinary meaning as understood by those of skill in the art, and thus refers to an assay in which an analyte of interest first binds to its specific antibody or antigen to form a complex, and then a second antibody, analyte, or compound binds to the complex to provide a detectable signal. In some embodiments, the first or "primary" antibody or antigen is unlabeled. In some embodiments, the analyte of interest is immobilized on a test strip. In some embodiments, the second antibody, analyte, or compound binds to the primary antibody or antigen. In some embodiments, the second antibody, analyte, or compound binds to the analyte. In some embodiments, the second antibody, analyte, or compound binds to the primary antibody or antigen that is in a complex with the analyte.

[0027] As used herein, the term "sandwich immunoassay" has its ordinary meaning as understood by those of skill in the art, whereby an antibody or antigen specific for an analyte of interest is immobilized on a test strip, the analyte of interest is then contacted in solution with the antibody or antigen to form a complex, and a second antibody, analyte, or compound binds to the complex to provide a detectable signal. In some embodiments, the first or "primary" antibody or antigen is labeled. In some embodiments, the second antibody, analyte, or compound binds to the primary antibody or antigen. In some embodiments, the second antibody, analyte, or compound binds to the analyte. In some embodiments, the second antibody, analyte, or compound binds to the primary antibody or antigen, which is in a complex with the analyte.

[0028] As used herein, the term "competitive immunoassay," also known as an "inhibition" or "suppression" immunoassay, has its ordinary meaning as understood by those of skill in the art and thus refers to an assay in which the concentration of an analyte of interest in a sample is measured by detecting interference in a predicted signal output.

[0029] Immunoassays described herein can include labels. Labels can take many different forms, including molecules or compositions that are bound or capable of being bound to an analyte, analyte analog, detection reagent, or binding partner detectable by spectroscopic, photochemical, biochemical, immunochemical, electrical, optical, or chemical means. Examples of labels include enzymes, colloidal gold particles (also called gold nanoparticles), colored latex particles, radioisotopes, cofactors, ligands, chemiluminescent or fluorescent agents, protein-adsorbed silver particles, protein-adsorbed iron particles, protein-adsorbed copper particles, protein-adsorbed selenium particles, protein-adsorbed sulfur particles, protein-adsorbed tellurium particles, protein-adsorbed carbon particles, and protein-bound dye capsules. Attachment of a compound (e.g., a detection reagent) to a label can be by covalent bonds, adsorptive processes, hydrophobic and / or electrostatic bonds, such as chelates, or the like, or by these bonds and interactions, and / or can include linking groups.

[0030] The term "specific binding partner (or binding partner)" refers to one of a pair of molecules that interact by specific non-covalent interactions that depend on the three-dimensional structures of the molecules involved. Exemplary specific binding partner pairs include antigen / antibody, partial antigen / antibody, hormone / receptor, nucleic acid strand / complementary nucleic acid strand, substrate / enzyme, inhibitor / enzyme, carbohydrate / lectin, biotin / (strept)avidin, receptor / ligand, and viral / cellular receptor, or various combinations thereof.

[0031] As used herein, the term "immunoglobulin" or "antibody" refers to a protein that binds a specific antigen. Immunoglobulins include, but are not limited to, polyclonal, monoclonal, chimeric, and humanized antibodies, Fab fragments, F(ab')2 fragments, and further include the following classes of immunoglobulins: IgG, IgA, IgM, IgD, IbE, and secretory immunoglobulin (sIg). Generally, immunoglobulins contain two identical heavy chains and two light chains. However, the terms "antibody" and "immunoglobulin" also encompass single-chain and two-chain antibodies.

[0032] The immunoassays described herein can be performed on a variety of compatible devices, materials, and platforms, including, but not limited to, base plates, well plates, polystyrene microtubes, microtiter plates, lateral flow assays, BD Veritor™ systems, Luminex assays, dry kits, ELISA assays, microarray assays, bead-based assays, fluorescent plate readers, luminescent plate readers, chemical plate readers, optical plate readers, chemiluminescent plate readers, and chip-based assays. Thus, although embodiments of the present disclosure are described in the context of immunoassay test strips, it should be understood that, in accordance with the present disclosure, the use of sample suitability markers to indicate sample suitability can also be performed in immunoassays that do not use a test strip format, including, but not limited to, assays performed using plate-based or well plate assays, Luminex assays, ELISA assays, bead-based assays, and microarray assays.

[0033] Lateral flow assay Some aspects of the present disclosure relate to a special type of immunoassay, the lateral flow assay. A lateral flow assay is an assay that can be performed on a lateral flow device as described herein. A lateral flow device as described herein is an analytical device used in lateral flow chromatography. A lateral flow device can be implemented on a test strip, although other configurations may be suitable. In a test strip format, a test sample fluid suspected of containing an analyte flows through the strip (e.g., by capillary action). The strip can be made of bibulous materials such as paper, nitrocellulose, and cellulose. The sample fluid is received in a sample reservoir. The sample fluid can flow along the strip to a capture zone, where the analyte (if present) interacts with a capture agent to indicate the presence, absence, and / or amount of the analyte. The capture agent can include an antibody immobilized in the capture zone.

[0034] Signals generated by assays according to the present disclosure are described herein in the context of optical signals generated by reflective labels, such as, but not limited to, gold nanoparticle labels. Although embodiments of the present disclosure are described herein with reference to "optical" signals, it should be understood that the assays described herein may use any material suitable for a label to generate a detectable signal, including, but not limited to, fluorescent latex bead labels, which generate fluorescent signals, and magnetic nanoparticle labels, which generate signals indicative of changes in a magnetic field associated with the assay.

[0035] Implementations of the present disclosure can detect analytes of interest or sample qualification markers occurring at various concentrations, including high concentrations. For example, embodiments of the present disclosure can detect analytes using the lateral flow devices, testing systems, and methods described in International Application PCT / US2018 / 039347, filed June 25, 2018, the entire disclosure of which is incorporated herein by reference. It should be understood that in embodiments implementing the lateral flow devices, testing systems, and methods described in International Application PCT / US2018 / 039347, filed June 25, 2018, the amount of detectable signal at the analyte capture line decreases, rather than increases, as the analyte of interest binds more strongly to the analyte capture line.

[0036] Sandwich and competitive lateral flow assays Lateral flow assays can be performed in a sandwich format or a competitive format. Although the sandwich and competitive format assays described herein will be described in the context of a reflectance label (such as a gold nanoparticle label) that generates an optical signal, it is understood that the assay can include a latex bead label configured to generate a fluorescent signal, a magnetic nanoparticle label configured to generate a magnetic signal, or any other label configured to generate a detectable signal. A sandwich type lateral flow assay includes a labeled antibody deposited in a sample reservoir on a solid substrate. After the sample is applied to the sample reservoir, the labeled antibody elutes into the sample, after which the antibody recognizes and binds to an epitope on an analyte in the sample, forming a label-antibody-analyte complex. This complex flows along a liquid front from the sample reservoir through the solid substrate to a capture zone (sometimes called a "test line") where an immobilized antibody (sometimes called a "capture agent") is positioned. In some cases where the analyte is multimeric or contains multiple equal epitopes on the same monomer, the labeled antibody deposited in the sample reservoir can be the same as the antibody immobilized in the capture zone. The immobilized antibody recognizes and binds to an epitope on the analyte, thereby capturing the label-antibody-analyte complex in the capture zone. The presence of the labeled antibody in the capture zone provides a detectable optical signal in the capture zone. In one non-limiting example, gold nanoparticles are used to label the antibody because gold nanoparticles are relatively inexpensive, stable, and produce an easily observable color based on their surface plasmon resonance properties. In some embodiments, this signal provides qualitative information, such as whether the analyte is present in the sample. In some cases, this signal provides quantitative information, such as a measurement of the amount of analyte in the sample.

[0037] Sample suitability markers In some embodiments, the sample is an environmental sample for detecting an analyte in the environment. In some embodiments, the sample is a biological sample from a subject. In some embodiments, the sample is a fluid. In some embodiments, the biological sample can include blood, peripheral blood, serum, plasma, ascites, urine, cerebrospinal fluid (CSF), sputum, saliva, bone marrow, synovial fluid, aqueous humor, amniotic fluid, earwax, breast milk, bronchoalveolar lavage fluid, semen (including prostatic fluid), Cowper's or pre-ejaculatory fluid, Bartholin's gland fluid, sweat, feces, hair, tears, cyst fluid, pleural and peritoneal fluid, pericardial fluid, lymph, chyme, chyle, bile, interstitial fluid, menstrual fluid, pus, sebum, vomit, vaginal secretions, mucosal secretions, nasal secretions, mucus, watery stool, pancreatic juice, sinus lavage, bronchopulmonary aspirate, or other lavage fluids.

[0038] As used herein, a "sample suitability marker" is an analyte, molecule, compound, or substance that can be used to assess the quantity, quality, and / or composition of the sample from which it originated. In conventional immunoassays, a negative result is obtained either when the analyte of interest is not present in the sample or when the sample is of insufficient suitability. In the present disclosure, a positive detection of a sample suitability marker indicates that the sample is present in the immunoassay and is intact at a high enough concentration to trigger detection. Sample suitability markers can be any that are inherent to the sample, including constitutive molecules, endogenous molecules, and "housekeeping" molecules. Examples of sample suitability markers include, but are not limited to, protein, total protein, albumin, serum albumin, human albumin, lactotransferrin (lactoferrin), actin, lysozyme, IgA, hemoglobin, mucin, mucin 7, mucin 5ac, mucin 20, trefoil factor 3, cell, cell particle, ammonium, acid phosphate, calcium, proline-rich protein family, salivary amylase, hormones, apolipoprotein D, clusterin, exocrine protein, and dermcidin.

[0039] Immunoassay test strips Immunoassay test strips according to the present disclosure can be used to detect, identify, and in some cases, quantify biological agents. Biological agents include chemical or biochemical compounds produced by living organisms, which may include prokaryotic cell lines, eukaryotic cell lines, mammalian cell lines, microbial cell lines, insect cell lines, plant cell lines, mixed cell lines, naturally occurring cell lines, or synthetically engineered cell lines. Biological agents can include macromolecules such as proteins, polysaccharides, lipids, and nucleic acids, as well as small molecules such as primary metabolites, secondary metabolites, and natural products.

[0040] As disclosed herein, a sample is administered to the test strip through a flow path. In some embodiments, the sample is added to a buffer or solution prior to administration into the flow path. The sample then travels along the flow path into the sample receiving zone. In some embodiments, the test strip includes a negative control line that functions to distinguish non-specific signals from binding of the analyte of interest to the antibody, analyte, or compound. In some embodiments, the test strip includes a positive control line that displays an optimal signal for binding. Both the positive and negative control lines can verify the integrity of the immunoassay, ensure proper reagent function, and verify correct testing procedures. Although some non-limiting implementations of the present disclosure are described in connection with a test strip that includes a test line, a sample qualification line, a positive control line, and a negative control line, it should be understood that implementations of the present disclosure need not include a positive and / or negative control line. In some non-limiting embodiments, the sample qualification line serves the same or similar function as the positive control line in addition to indicating whether the sample is sufficient or valid.

[0041] Certain aspects of the present disclosure include capture agents. Capture agents include immobilization agents capable of binding to analytes, including free (unlabeled) analytes and / or labeled analytes. Capture agents include unlabeled specific binding partners that are (i) specific for the labeled analyte of interest, (ii) specific for the labeled analyte or unlabeled analyte, such as in a competitive assay, or (iii) an auxiliary specific binding partner, such as in an indirect assay, that is specific for a binding partner that is itself specific for the analyte. As used herein, an "auxiliary specific binding partner" is a specific binding partner that binds to the specific binding partner of the analyte. For example, an auxiliary specific binding partner can include an antibody specific for another antibody, such as a goat anti-human antibody. The immunoassay test strips described herein can include a "capture line," which is a region of the lateral flow device where a capture reagent is immobilized. The immunoassay test strips described herein can include two or more capture zones, e.g., a "primary capture zone," a "secondary capture zone," and the like. In some examples, different capture reagents can be immobilized within the primary, secondary, and / or other capture zones. These multiple capture areas can have any orientation relative to one another on the lateral flow substrate, for example, a primary capture area can be distal or proximal to a secondary (or other) capture area along the path of the fluid flow, or vice versa. Alternatively, the primary and secondary (or other) capture areas can be aligned along an axis perpendicular to the path of the fluid flow such that fluid can contact the capture areas simultaneously or nearly simultaneously.

[0042] In some embodiments, the capture agent is immobilized such that its movement is restricted during normal operation of the immunoassay test strip. For example, movement of the immobilized capture agent is restricted before and after a fluid sample is applied to the immunoassay test strip. Immobilization of the capture agent can be achieved by physical means such as a barrier, electrostatic interactions, hydrogen bonding, bioaffinity, covalent interactions, or a combination thereof.

[0043] The test strips described herein further comprise an analyte capture line and a sample qualification line. The analyte capture line binds and immobilizes at least one analyte of interest using at least one capture agent. In some embodiments, binding of the analyte of interest to the analyte capture line generates a detectable signal. Several embodiments of the sample qualification line of the present disclosure are configured to bind and immobilize at least one sample qualification marker using at least one capture agent. In some embodiments, binding of the sample qualification marker to the sample qualification line generates a detectable signal. In some embodiments, the signal generated by the analyte capture line is measurably different from the sample qualification line. In some embodiments, at least one signal is a fluorescent signal. In some embodiments, at least one signal is a chemiluminescent signal. In some embodiments, at least one signal is a luminescent signal. In some embodiments, at least one signal is a magnetic signal.

[0044] Some embodiments of the present disclosure may include a lateral flow assay that includes four different lines. For example, the positive control line, the negative control line, the analyte capture line, and the sample qualification line may be present in any order and arranged at any distance relative to each other on the test strip. In some embodiments, the lines are distributed such that the lines that induce a strong signal are sufficiently spaced apart from the lines that induce a weak signal. It should be understood that the positive control line and / or the negative control line may not be included in a lateral flow assay according to the present disclosure, and the sample qualification line according to the present disclosure may be positioned at any location along the flow path relative to the analyte capture line and any control lines that may be present.

[0045] As disclosed above, binding of the analyte of interest or sample suitability marker to the capture line results in a detectable signal or change in signal, thereby allowing identification of the presence of the analyte of interest and / or sample suitability marker in the sample. Some embodiments of the present disclosure include a sample suitability line configured to indicate the presence or absence of the sample suitability marker in the sample. Other embodiments of the present disclosure include a sample suitability line configured to indicate the amount or concentration of the sample suitability marker in the sample. In some embodiments, an indication of the presence or absence of the sample suitability marker in the sample is configured to be visually read or interpreted by a user observing the sample suitability line. In some embodiments, the presence of at least one sample suitability marker is not indicated or detected, in which case the test strip or a device detecting a signal emitted therefrom can display an indication that the sample is of insufficient quality. In some embodiments, the presence of at least one sample suitability marker is indicated or detected, in which case the test strip or a device detecting a signal emitted therefrom can display an indication that the sample is of sufficient quality. In some embodiments, the presence of at least one sample suitability marker is indicated or detected at a high concentration, in which case the test strip or a device detecting a signal emitted therefrom can display an indication that the sample suitability marker is present at a high concentration. In some embodiments, the presence of at least one sample suitability marker is indicated or detected at a low concentration, in which case the test strip or a device detecting a signal emitted therefrom can display an indication that the sample suitability marker is present at a low concentration. In some embodiments, the presence of at least one sample suitability marker is indicated or detected and the presence of at least one analyte of interest is not indicated or detected, in which case the test strip or a device detecting a signal emitted therefrom can display an indication that the at least one analyte of interest is not present or is not present in an amount above the limit of detection.In some embodiments, the presence of at least one sample suitability marker is indicated or detected and the presence of at least one analyte of interest is indicated or detected, where the test strip or device detecting the signal emitted therefrom can display an indication that the analyte of interest is present. In some embodiments, the presence of at least one sample suitability marker is indicated or detected and the presence of at least one analyte of interest is indicated or detected at a high concentration, where the test strip or device detecting the signal emitted therefrom can display an indication that the analyte of interest is present at a high concentration. In some embodiments, the presence of at least one sample suitability marker is indicated or detected and the presence of at least one analyte of interest is indicated or detected at a low concentration, where the test strip or device can display an indication that the analyte of interest is present at a low concentration. In some embodiments, the presence of at least one sample suitability marker is indicated or detected, and further the presence of a first one of the at least one analyte of interest is indicated or detected, and the presence of a second one of the at least one analyte of interest is not indicated or detected, in which case the test strip or a device detecting a signal emitted therefrom can display an indication that the first one of the at least one analyte of interest is present and that the second one of the at least one analyte of interest is not present or is not present in an amount above the limit of detection.

[0046] The test strips and / or cartridges described herein can be adapted for performing diagnostic and / or non-diagnostic tests. In some embodiments, the embodiments of the present disclosure can be implemented in conjunction with systems such as the BD Veritor™ at-home COVID-19 test, the BD Veritor™ system for rapid detection of SARS-CoV-2, the BD Veritor™ system for rapid detection of Influenza A+B, the BD Veritor™ system for rapid detection of Respiratory Syncytial Virus (RSV), the BD Veritor™ system for rapid detection of Group A Streptococcus, the BD Veritor™ system, the BD Veritor Plus™ system, and / or components or operations thereof. It should be understood that the embodiments of the present disclosure can be implemented in conjunction with any suitable detection system. In some non-limiting examples, the test results are read using visual observation of the test strip.

[0047] Immunoassay test strips according to the present disclosure can be included as components in a multiplex assay. A multiplex assay includes an assay that can detect, identify, and in some cases quantitate, multiple different analytes of interest. For example, within a multiplex assay device, there can be primary, secondary, or more capture zones, each specific for one of the multiple analytes of interest. In one non-limiting example, embodiments of the present disclosure detect a first analyte of interest, including but not limited to SARS-CoV-2, a second analyte of interest, including but not limited to influenza A, a third analyte of interest, including but not limited to influenza B, or any combination of these analytes of interest.

[0048] Methods of diagnosing disease conditions using immunoassays according to the present disclosure Some embodiments presented herein relate to methods of diagnosing a medical condition using an immunoassay. In some embodiments, the method includes providing an immunoassay as described herein. In some embodiments, the method includes receiving a sample into a sample reservoir of the immunoassay.

[0049] In some embodiments, the sample is obtained from a source, including an environmental source or a biological source. In some embodiments, the sample is suspected of having the analyte of interest. In some embodiments, the sample is not suspected of having the analyte of interest. In some embodiments, the sample is obtained and analyzed to verify the absence or presence of the analyte. In some embodiments, the sample is obtained and analyzed for the amount of the analyte therein. In some embodiments, the amount of the analyte in the sample is below, near, or above the normal value present in a healthy subject.

[0050] In some embodiments, receiving the sample into a sample reservoir of an immunoassay includes contacting the sample with the immunoassay. The sample can be contacted with the immunoassay by introducing the sample into the sample reservoir by external application, as with a dropper or other applicator. In some embodiments, the sample reservoir can be directly immersed in the sample, such as when a test strip is immersed into a container that holds the sample. In some embodiments, the sample can be poured, dripped, sprayed, placed, or otherwise contacted into the sample reservoir.

[0051] [Example 1] Among the preliminary biomarker candidates initially selected for evaluation, it was determined that either albumin or lactoferrin would ensure the collection of viable nasal samples and thereby the quality of the associated antigen assay. The incorporation of human biomarkers into rapid antigen tests for SARS-CoV-2 would ensure that diagnostic tests for non-laboratory use by individuals could be deployed in non-laboratory settings, such as at home.

[0052] The following example describes the preparation and use of a lateral flow assay according to the present disclosure. This non-limiting example describes the use of a lateral flow sandwich assay for human serum albumin (HSA) in at-home COVID-19 testing. This type of assay would require the end user (subject), in this case an untrained individual, to collect a swab sample from their own nasal cavity (or the nose of another individual who is the subject) without the assistance or direction of a skilled health care provider. A portion of a test strip 100 according to this non-limiting example of a lateral flow assay is shown in FIG.

[0053] To prepare a lateral flow assay, an anti-HSA antibody is streaked on the sample qualification line located at the L5 position of the nitrocellulose membrane (solid phase) of the test strip 100, a positive control (PC) line is streaked at the L4 position, an anti-SARS-CoV-2 antibody is streaked on the analyte capture line located at the L2 position, and a negative control (NC) line is streaked at the L1 position. The L3 position is left blank in this example, but can be used for other antibodies, such as anti-influenza antibodies for influenza testing. The L1 position is upstream and the L5 position is downstream, so that the sample flows from the background area towards the L5 position. On the upstream side, the nitrocellulose membrane contacts a conjugate pad (not shown) on which anti-SARS-CoV-2 gold conjugates, anti-HSA gold conjugates, and PC line specific conjugates are deposited. The downstream side of the nitrocellulose membrane contacts an absorbent pad (not shown) that serves as an absorbent to facilitate the flow of the sample from the conjugate pad across the solid phase, in this case nitrocellulose.

[0054] Next, the use of the lateral flow assay is described. A user obtains a liquid sample from a nasal swab applied to the subject's nasal cavity. In one non-limiting example, the liquid sample includes an extraction reagent that contacts the nasal swab. In one non-limiting example, the extraction reagent contains a buffer to maintain a predetermined pH. The extraction reagent includes a saline solution and a surfactant to allow specific antibody-antigen binding to occur at this pH and to prevent or minimize the formation of non-specific antibody-antigen complexes. The surfactant also promotes the elution of the sample on the nasal swab into the extraction reagent. In another non-limiting example, the liquid sample does not include an extraction reagent. When the liquid sample or the extracted liquid sample from the nasal swab is applied to the conjugate pad, the antibody-gold conjugate deposited on the conjugate pad is rehydrated and becomes solubilized. A specific analyte, such as HSA present in the human nose, will bind to the antibody conjugated to the gold particles to form an HSA-antibody-gold complex and flow towards the reaction zone (in this case the sample qualification line positioned at the L5 position) where another anti-HSA antibody capable of capturing the HSA-antibody-gold complex is immobilized on the solid phase to form a sandwich, emitting a signal that can be visually observed by the end user, detected with a detector, and / or imaged for initial or further reading or other purposes.

[0055] If the swab associated with the sample is not inserted into the subject's nasal cavity or if the nasal cavity is very dry, proteins such as HSA from the nasal cavity will be absent or present at very low concentrations. In this case, the capture antibody-HSA-antibody-gold sandwich will not be formed or will be formed at less than detectable levels, and the sample suitability line located at the L5 position will indicate a negative result and an insufficient sample. Another exemplary scenario in which the sample suitability line located at the L5 position may indicate an insufficient sample is when the sample is taken from a subject who is unwilling or unwilling to allow the user to enter the swab into the nasal cavity (e.g., when the subject is a child). In this exemplary scenario, the swab cannot enter the subject's nasal cavity, or the swab cannot be inserted deep enough into the nasal cavity, or the swab cannot be inserted into the nasal cavity for a sufficient time and / or with sufficient contact. A further exemplary scenario in which a sample suitability line located at the L5 position may indicate that the sample is insufficient is when the sample is collected from a subject with sensitive and / or weak nasal passages. In this exemplary scenario, the swab cannot enter the subject's nasal passage, or the swab cannot be placed deep enough into the nasal passage, or the swab cannot be placed into the nasal passage for a sufficient time and / or with sufficient contact. Yet another exemplary scenario in which a sample suitability line located at the L5 position may indicate that the sample is insufficient is when the sample is collected using a swab other than one designated for lateral flow assays. For example, an end user may collect a sample using an unauthorized or inappropriate swab, which may lead to insufficient or inefficient collection of nasal secretions to generate a sufficient sample or the sample cannot be eluted into the extraction reagent due to the material used in the swab tip.

[0056] The SARS-CoV-2 assay works in the same or similar manner as the HSA assay described above. For example, in the presence of sufficient viral antigen, a capture antibody-SARS-CoV-2 antigen-antibody-detection agent complex will form on the analyte capture line at the L2 position and emit a detectable signal. In the absence of viral antigen, the sandwich will not form and no signal will be emitted at the analyte capture line or the signal emitted will be below the detection limit threshold. As long as the liquid phase flows through the PC line, the PC line specific conjugate will bind to the PC line and a visible line will be formed indicating that the assay is running properly and that the assay reagents are operational. If the subject's sample contains interfering substances such as human anti-mouse antibodies or high concentrations of rheumatoid factor, the NC line will emit a signal indicating that the assay should not be reported as positive or that the test result should be invalidated.

[0057] [Example 2] The embodiments of the present disclosure can indicate or detect the presence of albumin or lactoferrin in various detection ranges, allowing for a highly sensitive sample qualification test to confirm the collection of a viable nasal sample. In one non-limiting implementation of the lateral flow assay of the present disclosure, the sample qualification line indicates the presence of HSA in a sample having an amount of HSA ranging from about 50 ng / mL to about 1.5 μg / mL. Other HSA detection ranges are possible in embodiments of the present invention. In another non-limiting implementation of the lateral flow assay of the present disclosure, the presence of HSA in a sample having less than 50 ng / mL of HSA is indicated or detected at the sample qualification line. In yet another non-limiting implementation of the lateral flow assay of the present disclosure, the lower end of the detection limit for the presence of HSA in a sample is about 100 ng / mL of HSA. In a further non-limiting implementation of the lateral flow assay of the present disclosure, the presence of HSA in a sample having more than 1.5 μg / mL of HSA is indicated or detected at the sample qualification line. Embodiments of the present disclosure can also indicate or detect various ranges of lactotransferrin in a sample. In one non-limiting implementation of a lateral flow assay according to the present disclosure, the sample qualification line indicates the presence of lactotransferrin in a sample having about 10 ng / mL lactotransferrin.

[0058] [Example 3] Some embodiments of the present disclosure can use a combination of anti-HSA antibodies in the sample qualification line to indicate or detect the presence of HSA, allowing for indication or detection of very low concentrations of HSA in a sample. In one non-limiting implementation of the lateral flow assay according to the present disclosure, two anti-HSA antibodies are applied to the sample qualification line in a 50 / 50 ratio. The first anti-HSA antibody is A15374 supplied by BiosPacific, and the second anti-HSA antibody is catalog number 10C-CR2116M2, clone227425 supplied by Fitzgerald Industries International. This exemplary implementation resulted in a sample qualification line indicating the presence of HSA in samples with very low concentrations of HSA. It should be understood that anti-HSA antibodies from other sources can be suitably implemented in the sample qualification line according to the present disclosure. It should also be understood that ratios other than the 50 / 50 ratio of two different anti-HSA antibodies, and different combinations of different anti-HSA antibodies, may be suitably implemented in a sample suitability line according to the present disclosure.

[0059] [Example 4] The test results obtained from the lateral flow assay according to the present disclosure are now described. The test results are presented in FIG. 2, which is a frequency graph showing the distribution of measured sample suitability line intensities in AU (arbitrary units) for 369 fluid samples collected and analyzed using an exemplary immunoassay according to the present disclosure. In this experiment, the sample suitability line of the lateral flow assay according to the present disclosure was streaked with anti-HSA antibodies. A streaking solution containing 1.2 mg / mL of BiosPacific anti-HSA antibody A15374 and Fitzgerald's anti-HSA antibody 10C-CR2116M2 was deposited on the sample suitability line of the nitrocellulose membrane at a rate of 0.75 μL / cm, which corresponds to 0.41 μg of each of the two types of antibodies being deposited on the test device. The frequency graphs of the test results show that several embodiments of the sample suitability lines of the present disclosure can indicate with sufficient accuracy and reliability the presence or absence of a sample suitability marker, in this case HSA, in a sample to indicate whether the respective sample is suitable for the test.

[0060] [Example 5] Next, a clinical trial test obtained from a lateral flow assay according to the present disclosure is described. A non-limiting example shows the use of an assay including a sample qualification line according to the present disclosure to determine the presence of SARS-CoV-2 virus, the virus that causes the contagious respiratory disease COVID-19. Detection of the presence of SARS-CoV-2 in a sample from a subject can indicate that the subject is infected with the virus that causes COVID19. During a clinical trial conducted from March to May 2021, nasal swab samples were collected by clinical trial participants using the BD Veritor™ at-home COVID-19 test (Becton, Dickinson and Company, Franklin Lakes, NJ, USA), a quantitative test for the detection of SARS-CoV-2 viral proteins in nasal swabs. It is understood that an assay according to the present disclosure can be used in any type of detection assay that uses a swab to collect a sample.

[0061] In this clinical trial, study participants collected swab samples and the same participants tested using a lateral flow assay according to the present disclosure at eight point-of-care sites. It is understood that during non-clinical use of the BD Veritor™ at-home COVID-19 test, individuals using the test can collect nasal swab samples at home or other non-clinical settings and then test the collected samples using a lateral flow assay according to the present disclosure included in the test. The test can be administered at home and results can be obtained in approximately 15 minutes. Step-by-step instructions guide subjects through sample collection, sample processing, and immediate result reading from start to finish. In this clinical trial, subjects self-administered the BD Veritor™ at-home COVID-19 test at the point-of-care sites, or a parent / legal guardian / partner administered the swab, processed the sample, and read the test results without assistance as in a home environment, using only the information available in the associated app on a compatible smartphone, the product information insert, and the quick start guide.

[0062] The BD Veritor™ at-home COVID-19 test is designed for individuals to self- or self-administer for proteins from the virus that causes COVID-19. The test is authorized for home use without a prescription. The test is intended for use by individuals who are tested twice on two or three days with at least 24 hours and no more than 48 hours between tests, regardless of the presence or absence of symptoms or other epidemiological reasons for suspecting COVID-19. The test is intended for the qualitative detection of SARS-CoV-2 viral proteins in direct anterior nasal swab specimens from individuals 2-13 years of age when an adult uses the test to collect the specimen, and from individuals 14 years of age and older when self-collecting. Individuals over 14 years of age may also be collected by an adult. A positive test result using the BD Veritor™ at-home COVID-19 test indicates a very high probability that the individual tested has COVID-19 because proteins from the virus that causes COVID-19 were detected in the individual's specimen. A negative test result using the BD Veritor™ at-home COVID-19 test indicates that proteins from the virus that causes COVID-19 were not found in the tested individual's sample and that the individual is unlikely to have COVID-19. Even if the test result is negative, it is possible for the tested individual to have COVID-19.

[0063] 893 adult and pediatric human subjects were enrolled in the clinical trial. A swab sample was collected from each subject's nasal cavity using the swab provided with the BD Veritor™ at-home COVID-19 test. Samples were collected directly by either the test subject, the test subject's guardian, or a collaborator without assistance from a healthcare professional (HCP). Each sample was then analyzed using a lateral flow assay according to the present disclosure by the test subject, the test subject's guardian, or a collaborator. A reference swab was collected by the HCP, stored in transport media (Universal Viral Transport Media (UVT) by Becton, Dickinson and Company, Franklin Lakes, NJ, USA), and sent to the reference laboratory. The central reference laboratory tested the reference swabs using the Lyra SARS-CoV-2 Assay (Quidel, San Diego, CA, USA).

[0064] The lateral flow assay used in the clinical trial on test subjects was performed on a test strip similar to the test strip 100 described in Example 1 above with reference to FIG. 1. The lateral flow assay test strips were prepared according to Examples 3 and 4 above. For example, to prepare the lateral flow assay used in the clinical trial, an antibody was streaked on a sample suitability line located at the L5 position of the nitrocellulose membrane (solid phase) of a test strip similar to the test strip 100 described in Example 3. The L2 line was streaked with the test line antibody, in this case a recombinant rabbit monoclonal antibody (HyTest Ltd., Turku, Finland), at a concentration of 2.4 mg / mL and a streak speed of 0.75 μL / cm. Each test strip contained 0.814 μg of this antibody. A positive control (PC) line was streaked at the L4 position, a negative control (NC) line was streaked at the L1 position, and the L3 line was left blank, as described in Example 1. The L1 position was upstream and the L5 position was downstream so that the sample would flow from the background area towards the L5 position. On the upstream side, the nitrocellulose membrane was contacted with a conjugate pad on which the antibody-gold conjugate and the PC-line specific conjugate were deposited. The downstream side of the nitrocellulose membrane was contacted with an absorbent pad that served as an absorbent to facilitate the flow of the sample from the conjugate pad across the solid phase, in this case the nitrocellulose.

[0065] Each sample collected by a clinical trial participant was applied to a conjugate pad on an individual test strip provided within the BD Veritor™ at-home COVID-19 test. Participants read the test results unassisted as in the home environment using the associated app on a compatible smartphone, the product information insert, and the quick start guide. As disclosed in the examples above, samples that were applied to the test strip and contained sufficient amounts of viral antigen (e.g., at or above the limit of detection for the test) formed an antibody-COVID-19 antigen-antibody-detection agent complex on the analyte capture line at the L2 position to generate a signal (in AU units) that was detected using the BD Veritor™ at-home COVID-19 test application software implemented on a compatible smartphone. A detection signal above a threshold resulted in the sample being identified as containing SARS-CoV-2 viral antigen and the sample test result being reported as "positive" for COVID-19. Samples that did not contain sufficient amounts of viral antigen did not form such complexes and no signal (in AU) was detected at the analyte capture line. These samples were identified as not containing SARS-CoV-2 viral antigen and the sample test results were reported as "negative" for COVID-19. A visible line formed by the PC-line specific conjugate bound to the PC-line was used as a positive control for each sample, indicating that the assay was working properly and that the assay reagents were operational.

[0066] The signal in AU obtained from the lateral flow assay was measured and analyzed using the BD Veritor™ at-home COVID-19 test application software implemented on a compatible smartphone. The overall performance of the BD Veritor™ at-home COVID-19 test against the Lyra SARS-CoV-2 assay for symptomatic subjects was 81.3% PPA (positive percent agreement), 99.8% NPA (negative percent agreement), and 98.7% OPA (overall percent agreement). Figure 3 shows a histogram of the distribution of sample suitability line intensity in AU for samples analyzed during the clinical trial, with frequency on the y-axis and sample suitability line intensity on the x-axis. L5 (sample suitability line) values ​​ranged from 0.55 AU to 98.92 AU with a mean value of 58.17 AU. As shown in Figure 3, the measured intensity at the sample suitability line L5 of some test strips was zero or near zero (or the measured intensity was below the preset threshold or "cutoff" value for sample suitability), indicating that HSA was not detected even at very low concentrations in the samples (or that HSA was present at such low concentrations that it was only detected below the preset threshold or "cutoff" value for sample suitability). The absence of HSA in these samples (or the presence of HSA at concentrations below the threshold for sample suitability) indicated that these samples were insufficient. Example 1 above describes potential non-limiting reasons why these samples may be insufficient for testing.

[0067] During this clinical trial, a cutoff value of 10.4 AU was used as a threshold or cutoff value for assessing whether a particular sample was suitable for the test. For example, an intensity measurement value lower than 10.4 AU at the sample suitability line would result in the respective sample being deemed unsuitable since the measurement value is below the pre-set threshold or cutoff value established for this clinical trial. Such samples were assigned an "invalid" test result by the BD Veritor™ at-home COVID-19 test application software. An intensity measurement value higher than 10.4 AU at the sample suitability line would result in the respective sample being deemed suitable for the test since the measurement value is above the pre-set threshold or cutoff value established for this clinical trial. Such samples were assigned a "positive" test result, a "negative" test result, or, in some cases, an "invalid" test result if the test was invalid for reasons unrelated to the intensity measured at the sample qualification line (e.g., based on the intensity measured at the positive or negative control lines) by the BD Veritor™ at-home COVID-19 test application software. It is understood that the 10.4 AU threshold or cutoff value for sample qualification line intensity for this clinical trial is a non-limiting example and that other suitable cutoff values ​​can be implemented in embodiments of the present disclosure.

[0068] The results of this clinical trial clearly demonstrated that the lateral flow assay including the sample suitability line according to the embodiments of the present disclosure detects SARS-CoV-2 viral antigens in samples with sufficient accuracy and reliability to indicate whether each sample is suitable for the test. In most of the samples tested, the sample suitability line displayed strong intensity indicating that each sample was properly collected by the clinical trial participant. In two samples tested, the sample suitability line was very weak (0.55 AU and 6.59 AU). These two measurement intensities were below the 10.4 AU cutoff value for sample suitability established for this clinical trial. As a result, the BD Veritor™ at-home COVID-19 test application software determined the test results for these two samples to be "invalid." In the third sample tested, the measurement intensity at the sample suitability line was 15.09 AU, which is above the 10.4 AU cutoff value for sample suitability established for this clinical trial. As a result, the BD Veritor™ at-home COVID-19 test application software determined that the test result was suitable for testing, and in particular determined that the test result was "negative" based at least in part on the intensity measured at the analyte capture line at location L2 (0.000255 AU for this sample). For the test on the fourth sample, the measured intensity at the sample suitability line was 57.46 AU, which exceeds the 10.4 AU cutoff value for sample suitability established for this clinical trial. As a result, the BD Veritor™ at-home COVID-19 test application software determined that the test result was suitable for testing, and in particular determined that the test result was "positive" based at least in part on the intensity measured at the analyte capture line at location L2 (119.9 AU for this sample). In view of the above, this clinical trial demonstrated that in two samples, the sample suitability markers disclosed herein were not detected (or were only detected at levels below the threshold or cutoff value for sample suitability), indicating that the quantity, quality, and / or composition of the original samples were not suitable.In particular, this clinical trial demonstrated that in two cases, clinical trial participants did not obtain samples with a quantity, quality, and / or composition suitable for testing.

[0069] It should be understood that the specification, specific examples, and data, while indicating exemplary embodiments, are presented by way of illustration and are not intended to limit the various embodiments of the disclosure. Various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from the description and data contained herein and are therefore considered part of the various embodiments of the disclosure.

Claims

1. a flow path configured to receive a sample; a sample receiving zone coupled to the flow path; At least one sample fitness line; at least one analyte capture line; 1. An immunoassay test strip comprising:

2. 10. The immunoassay test strip of claim 1, wherein the sample comprises at least one sample qualification marker, the at least one sample qualification marker in the sample comprises human albumin, and the at least one sample qualification line comprises an anti-HSA antibody.

3. 10. The immunoassay test strip of claim 1, wherein the sample comprises at least one sample suitability marker, the at least one sample suitability marker in the sample comprises lactotransferrin, and the at least one sample suitability line comprises an anti-lactotransferrin antibody.

4. 4. The immunoassay test strip of claim 2 or 3, wherein the presence and abundance of the at least one sample suitability marker in the sample depends on the quantity, quality, and / or composition of the sample.

5. The immunoassay test strip of claim 4, wherein the sample further comprises at least one analyte of interest, and the presence and abundance of the at least one sample suitability marker in the sample is dependent on the disease state of the donor.

6. 6. The immunoassay test strip of claim 5, wherein the at least one analyte of interest in the sample comprises a marker for an infectious disease, a viral marker, a marker for SARS-CoV-2, a marker for influenza, a marker for influenza A virus, or a marker for influenza B virus, the immunoassay performed at the at least one sample qualification line is a sandwich-type lateral flow assay, and the immunoassay performed at the at least one analyte capture line is a sandwich-type lateral flow assay.

7. 6. The immunoassay test strip of claim 5, wherein the at least one analyte of interest in the sample comprises a marker for influenza and a marker for SARS-CoV-2, the immunoassay performed at the at least one sample qualification line is a sandwich-type lateral flow assay, and the immunoassay performed at the at least one analyte capture line is a sandwich-type lateral flow assay.

8. 2. The immunoassay test strip of claim 1, wherein the test strip comprises a positive control line positioned on the test strip between the at least one analyte capture line and the at least one sample qualification line, between the at least one analyte capture line and a negative control line, or between the at least one sample qualification line and the negative control line.

9. 1. A method for assessing sample suitability using an immunoassay test strip comprising a flow path configured to receive a sample, a sample receiving zone coupled to the flow path, at least one sample suitability line, and at least one analyte capture line, comprising: applying the sample to the immunoassay test strip; flowing the sample through the flow path to the sample receiving zone; monitoring the presence of at least one analyte of interest in said sample by an immunoassay performed at said at least one analyte capture line; monitoring the presence of at least one sample suitability marker in said sample by an immunoassay performed at said at least one sample suitability line; Including, A method, wherein detection of said at least one sample suitability marker is used as an indication of the quantity, quality and / or composition of said sample.

10. 10. The method of claim 9, wherein the sample comprises at least one sample qualification marker, the at least one sample qualification marker in the sample comprises human albumin, and the at least one sample qualification marker in the sample comprises an anti-HSA antibody.

11. 10. The method of claim 9, wherein the sample comprises at least one sample suitability marker, the at least one sample suitability marker in the sample comprises lactotransferrin, and the at least one sample suitability line comprises an anti-lactotransferrin antibody.

12. The method of claim 9, wherein the sample contains at least one analyte of interest, and the presence and abundance of the at least one sample suitability marker in the sample depends on the disease state of the donor.

13. 13. The method of any one of claims 9 to 12, wherein the sample is selected from the group consisting of a nasal sample, a mucus sample, a blood sample, a plasma sample, a urine sample, a sweat sample, or a saliva sample taken from a donor.

14. 14. The method of any one of claims 9 to 13, wherein the at least one analyte of interest in the sample comprises a marker for an infectious disease, a viral marker, a marker for SARS-CoV-2, a marker for influenza, a marker for influenza A virus, or a marker for influenza B virus, the immunoassay performed at the at least one sample qualification line is a sandwich lateral flow assay, and the immunoassay performed at the at least one analyte capture line is a sandwich lateral flow assay.

15. 13. The method of claim 12, wherein the at least one analyte of interest in the sample comprises a marker for influenza and a marker for SARS-CoV-2, the immunoassay performed at the at least one sample qualification line is a sandwich-type lateral flow assay, and the immunoassay performed at the at least one analyte capture line is a sandwich-type lateral flow assay.

16. 10. The method of claim 9, wherein the test strip comprises a positive control line positioned on the test strip between the at least one analyte capture line and the at least one sample qualification line, between the at least one analyte capture line and a negative control line, or between the at least one sample qualification line and the negative control line.

17. 17. The method of any one of claims 9 to 16, wherein if the presence of the at least one sample suitability marker is not detected, the method further comprises displaying an indication that the sample is of insufficient quality.

18. 17. The method of any one of claims 9 to 16, wherein if the presence of the at least one sample suitability marker is detected, the method further comprises displaying an indication that the sample is of sufficient quality.

19. 20. The method of claim 18, wherein if the presence of the at least one sample suitability marker is detected in a high concentration, the method further comprises displaying an indication that the sample is present in a high concentration.

20. 20. The method of claim 18, wherein if the presence of the at least one sample suitability marker is detected at a low concentration, the method further comprises displaying an indication that the sample is present at a low concentration.

21. 21. The method of any one of claims 18 to 20, wherein if the presence of the at least one sample suitability marker is detected and the presence of the at least one analyte of interest is not detected, the method further comprises the step of displaying an indication that the at least one analyte of interest was not detected.

22. 21. The method of any one of claims 18 to 20, wherein if the presence of the at least one sample suitability marker is detected and the presence of the at least one analyte of interest is detected, the method further comprises displaying an indication that the analyte of interest is present.

23. 23. The method of claim 22, wherein if the presence of the at least one sample suitability marker is detected and the presence of the at least one analyte of interest is detected at an elevated concentration, the method further comprises displaying an indication that the analyte of interest is present at an elevated concentration.

24. 23. The method of claim 22, wherein if the presence of the at least one sample suitability marker is detected and the presence of the at least one analyte of interest is detected at a low concentration, the method further comprises displaying an indication that the analyte of interest is present at a low concentration.

25. 25. The method of any one of claims 22 to 24, wherein if the presence of the at least one sample suitability marker is detected, the presence of a first one of the at least one analyte of interest is detected, and the presence of a second one of the at least one analyte of interest is not detected, the method further comprises displaying an indication that the first one of the at least one analyte of interest is present and the second one of the at least one analyte of interest is not detected.

26. 26. The method of any one of claims 9 to 25, wherein monitoring the presence of the at least one sample suitability marker in the sample comprises visually observing the at least one sample suitability line for the presence of an optical signal.

27. 27. The method of any one of claims 9 to 26, wherein monitoring the presence of the at least one analyte of interest in the sample comprises visually observing the at least one analyte capture line for the presence of an optical signal.

28. 26. The method of any one of claims 9 to 25, wherein monitoring the presence of the at least one sample qualification marker in the sample comprises obtaining an image of the at least one sample qualification line.

29. 26. The method of claim 9, wherein monitoring for the presence of the at least one analyte of interest in the sample comprises acquiring an image of the at least one analyte capture line.

30. An immunoassay test strip according to any one of claims 1 to 8; computer readable code identifying a software application configured to analyze an image of the immunoassay test strip to determine a test result based at least in part on the at least one sample qualification line; A test kit comprising:

31. 31. The test kit of claim 30, wherein the test result determined by the software application is an invalid test result based at least in part on the software application determining that an intensity of an optical signal from the at least one sample qualification line is below a preset threshold.

32. 31. The test kit of claim 30, wherein the test result determined by the software application is a valid test result based at least in part on the software application determining that an intensity of an optical signal from the at least one sample qualification line exceeds a preset threshold.

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