Multiplanar Lateral Flow Assay with Sample Compressor

• US 20110136258A1
• Filed: 12/02/2010
• Published: 06/09/2011
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: Rapid Pathogen Screening, Inc
• Original Assignee: Rapid Pathogen Screening, Inc
• Inventors: Kanaujia, Ganga V., Orsini, Thomas, Sambursky, Robert P., VanDine, Robert W., Babu, Uma Mahesh
• Granted Patent: US 8,609,433 B2
• Time in Patent Office: Days
• US Class Current: 436/501
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2400/0633 with moving parts
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: G01N 33/5302 Apparatus specially adapted for immunological test procedures
• CPC Class Codes: G01N 33/543 with an insoluble carrier for immobilising immunochemicals
• CPC Class Codes: G01N 33/54306 Solid-phase reaction mechanisms
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: Y02A 50/30 Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change
• CPC Class Codes: Y10T 436/25 including sample preparation

Abstract

A sample compressor applies pressure to a sample collector and a sample application zone of a test strip to transfer a sample from the sample collector and a binding partner of an analyte to the sample application zone in a lateral flow device. At least one of the binding partners of the analyte is not located on the test strip prior to use of the lateral flow device. The test strip may be a universal test strip with no molecule that specifically binds the analyte is located on the test strip. The sample compressor may be a universal sample compressor also with no molecule that specifically binds the analyte on the sample compressor. The lateral flow device may also include one or more enhancement elements, where the enhancement elements bind to the analyte sandwich to increase a detection signal in the test zone.

Claims

1. A lateral flow device for detecting an analyte in a sample comprising:

a sample compressor;

a sample collector comprising a sample collection portion for collection of the sample;

a test strip comprising a sample application zone and a test zone;

a conjugate comprising a first binding partner for the analyte and a label; and

a second binding partner for the analyte;

wherein a component selected from the group consisting of the conjugate, the second binding partner and both the conjugate and the second binding partner is not located on the test strip prior to use of the lateral flow device; and

wherein the sample compressor, the sample collector, and the test strip form a vertical stack to apply the sample to the test strip by compression;

wherein the sample collector is located between the sample compressor and the test strip in the vertical stack.

2. The lateral flow device of claim 1, wherein the sample compressor comprises a pad and wherein the conjugate or the second binding partner is located on the pad prior to use of the lateral flow device.

3. The lateral flow device of claim 2 further comprising a first control binding partner located on the pad and a second control binding partner immobilized in a control zone of the test strip, wherein the first control binding partner is a binding partner for the second control binding partner.

4. The lateral flow device of claim 2, wherein the conjugate is located on the pad and the second binding partner is located on an external medium.

5. The lateral flow device of claim 2, wherein the second binding partner is located on the pad and the conjugate is located on an external medium.

6. The lateral flow device of claim 1, wherein the lateral flow device is formed such that a positive result is only achieved by capture of the analyte in the test zone through formation of a complex between the analyte, the first binding partner, and the second binding partner.

7. The lateral flow device of claim 1, wherein the test zone comprises no molecule which specifically binds the analyte.

8. The lateral flow device of claim 1, wherein the second binding partner comprises a tag and the test zone comprises an immobilized binding partner of the tag.

9. The lateral flow device of claim 1 further comprising a housing surrounding at least a portion of the test strip, wherein a rotatable portion of the housing forms the sample compressor.

10. The lateral flow device of claim 1 further comprising a housing surrounding at least a portion of the test strip, wherein an insertable cartridge forms the sample compressor.

11. A universal test strip for use in a lateral flow device, the universal test strip comprising a test zone and comprising no molecule which specifically binds an analyte.

12. The universal test strip of claim 11 further comprising a control zone and a control binding partner immobilized in the control zone.

13. The universal test strip of claim 11 further comprising a tag immobilized in the test zone.

14. The universal test strip of claim 11, wherein the tag comprises a molecule selected from the group consisting of biotin, avidin, neutravidin, streptavidin, a lectin, and a glycosyl moiety.

15. A sample compressor for use in a lateral flow device, the sample compressor comprising a pad and at least one binding partner on the pad, wherein the binding partner binds an analyte.

16. The sample compressor of claim 15 further comprising a mobile control binding partner on the pad.

17. A universal sample compressor for use in a lateral flow device, the sample compressor comprising no molecule which specifically binds an analyte.

18. The universal sample compressor of claim 17 further comprising a pad and a mobile control binding partner on the pad.

19. A lateral flow device for detecting an analyte comprising:

a test strip comprising a sample application zone and a test zone;

a first conjugate comprising a first binding partner for the analyte;

a second binding partner for the analyte; and

an enhancement element;

wherein the analyte, the conjugate, and the second binding partner form a sandwich which is immobilized in the test zone when the analyte is present; and

wherein the enhancement element binds to the sandwich to increase a detection signal in the test zone.

20. The lateral flow device of claim 19, wherein the first conjugate further comprises a label.

21. The device of claim 19, wherein the first conjugate further comprises colloidal gold and the enhancement element comprises at least one silver salt.

22. The device of claim 19, wherein the enhancement element comprises an antigen and the first conjugate further comprises a specific binding partner for the antigen.

23. The device of claim 19, wherein the enhancement element further comprises a label.

24. The lateral flow device of claim 19, wherein the test zone comprises no molecule which specifically binds the analyte.

25. The lateral flow device of claim 19, wherein the second binding partner comprises a tag and the test zone comprises an immobilized binding partner of the tag.

26. The lateral flow device of claim 19, wherein:

the first binding partner for the analyte comprises a mixture of the first binding partner for the analyte conjugated to a tag and the first binding partner for the analyte without the tag;

the second binding partner for the analyte is immobilized in the test zone; and

wherein the enhancement element comprises a second conjugate comprising a label and a binding partner for the first binding partner for the analyte.

27. The lateral flow device of claim 26, wherein approximately 1-10% of the first binding partner for the analyte is conjugated to a tag.

28. The lateral flow device of claim 27, further comprising a tag binding partner with a detectable label, wherein when the tag binding partner is added to the test at the test zone, it increases a detection signal in the presence of analyte.

29. The lateral flow device of claim 19, wherein the enhancement element comprises an enzyme.

30. A method of applying a sample to a test strip of a lateral flow device, the method comprising the steps of:

a) placing a sample collector comprising a sample collection portion with the sample in a vertical stack between a sample compressor and a sample application zone of the test strip; and

b) applying a pressure to the sample collection portion using the sample compressor to transfer at least a portion of the sample to the sample application zone.

31. The method of claim 30, wherein the sample compressor comprises a component selected from the group consisting of a first binding partner, a second binding partner and both the first binding partner and the second binding partner.

32. The method of claim 30, wherein the sample collector delivers the sample passively by contact or through pressure onto the test strip prior to applying the sample compressor to the vertical stack.

33. The method of claim 30, wherein step a) further comprises placing a pad with a binding partner for an analyte on the vertical stack and wherein in step b) at least a portion of the binding partner is transferred to the sample application zone.

34. The method of claim 30, wherein step b) occurs without flow.

35. A lateral flow device for detecting an analyte in a sample comprising:

a sample compressor;

a sample collector comprising a sample collection portion for collection of the sample;

a test strip comprising a sample application zone and a test zone;

a conjugate comprising a first binding partner for the analyte and a label; and

a second binding partner for the analyte;

wherein a component selected from the group consisting of the conjugate, the second binding partner and both the conjugate and the second binding partner is not located on the test strip prior to use of the lateral flow device; and

wherein the sample compressor, the sample collector, and the component not on the test strip prior to use of the lateral flow device form a vertical stack to apply the sample to the test strip by compression.

36. The lateral flow device of claim 35, further comprising at least one external pad, wherein the component not on the test strip prior to use of the lateral flow device is located on the external pad.

37. A lateral flow device for detecting an analyte in a sample comprising:

a sample compressor;

a sample collector comprising a sample collection portion for collection of the sample;

a test strip comprising a sample application zone and a test zone;

a conjugate comprising a first binding partner for the analyte and a label; and

a second binding partner for the analyte;

wherein a component selected from the group consisting of the conjugate, the second binding partner and both the conjugate and the second binding partner is not located on the test strip prior to use of the lateral flow device; and

wherein the conjugate and the second binding partner come into contact with the sample after pressure transfers the sample onto the test strip.

38. A method of enhancing a signal on a lateral flow device comprising a test strip comprising a sample application zone and a test zone, a conjugate comprising a first binding partner for an analyte in a sample and a label, a second binding partner for the analyte;

and an enhancement element, comprising the steps of;

a) immobilizing a sandwich formed between the analyte, if present in the sample, the conjugate, and the second binding partner in a test zone of the lateral flow device; and

b) binding the enhancement element to the sandwich such that the enhancement element increases a detection signal in the test zone.

39. The method of claim 38, wherein step b) comprises the substep of adding the enhancement element directly to the test zone after the sandwich has reached the test zone.

40. The method of claim 38, wherein the enhancement element is in a volatile liquid.

41. The method of claim 38, wherein the conjugate further comprises colloidal gold and the enhancement element comprises at least one silver salt.

42. The method of claim 38, wherein the enhancement element comprises an antigen and the conjugate further comprises a specific binding partner for the antigen.

43. The device of claim 38, wherein the enhancement element further comprises a label.

44. The method of claim 38, wherein the test zone comprises no molecule which specifically binds the analyte.

45. A method of detecting at least one analyte in a sample using a point-of-care assay device, the method comprising the steps of:

a) adding a sample to a sample application zone of a chromatographic test strip;

b) after step a), adding at least one labeled first binding partner for the analyte to the sample application zone such that, if the analyte is present in the sample, a first analyte complex forms between the first binding partner and the analyte;

c) exposing the sample to at least one second tagged binding partner for the analyte;

wherein, when the analyte is present, steps a) through c) result in the formation of a second analyte complex between the first binding partner, the analyte, and the second binding partner; and

d) capturing the second analyte complex with an immobilized tag in a detection zone of the chromatographic test strip, wherein the immobilized tag complexes with a tag portion of the second binding partner.

46. The method of claim 45, wherein the first analyte complex forms without an addition of buffer to the test strip.

47. The method of claim 46, wherein the second analyte complex forms without the addition of buffer to the test strip.

48. The method of claim 45, wherein the point-of-care device comprises the chromatographic test strip, a sample compressor comprising at least the labeled first binding partner, and a sample collector for collecting the sample, wherein the sample compressor, the sample collector, and the chromatographic test strip form a vertical stack to apply the sample to the test strip by compression.

49. The method of claim 48, wherein the sample collector delivers the sample passively by contact or through pressure onto the test strip prior to applying the sample compressor to the vertical stack.

50. The method of claim 45, wherein a tag on the second binding partner and the immobilized tag comprise a pair selected from the group consisting of:

a) a first biotin tag and a second immobilized tag selected from the group consisting of avidin, neutravidin and streptavidin;

b) a first tag selected from the group consisting of avidin, neutravidin and streptavidin and a second biotin immobilized tag;

c) a first lectin tag and a second glycosyl moiety immobilized tag; and

d) a first glyosyl moiety tag and a second lectin immobilized tag.