Diagnostic test kits employing an internal calibration system

• US 20060223193A1
• Filed: 03/30/2005
• Published: 10/05/2006
• Est. Priority Date: 03/30/2005
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Song, Xuedong, Chidebelu-Eze, Chibueze Obi, Kaylor, Rosann Marie Matthews
• Granted Patent: US 7,939,342 B2
• Time in Patent Office: Days
• US Class Current: 436/514
• 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: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• CPC Class Codes: Y10T 436/105831 Protein or peptide standard or control [e.g., hemoglobin, etc.]

Abstract

A diagnostic test kit that employs a lateral flow assay device and a plurality of assay reagents for detecting a test analyte within a test sample is disclosed. The assay reagents include detection probes that are capable of producing a detection signal representing the presence or quantity of the test analyte in the test sample. To further enhance detection accuracy, calibration probes are also used that are capable of producing a calibration signal representing the presence or quantity of a calibration analyte. The calibration signal may be utilized to calibrate the detection signal.

Claims

1. A diagnostic test kit for detecting the presence or quantity of a test analyte within a test sample, the diagnostic test kit comprising:

a lateral flow assay device comprising a porous membrane, the porous membrane defining a detection zone and a calibration zone, wherein a first receptive material is immobilized within the detection zone and a second receptive material is immobilized within the calibration zone; and

a plurality of assay reagents, one or more of which are disposed on the lateral flow assay device, wherein the assay reagents comprise a calibration analyte, detection probes, and calibration probes, the detection probes being conjugated with a first specific binding member configured to preferentially bind to the test analyte, the first receptive material, or combinations thereof, and the calibration probes being conjugated with a second specific binding member configured to preferentially bind to the calibration analyte, the second receptive material, or combinations thereof.

2. The diagnostic test kit of claim 1, wherein the detection probes comprise a luminescent compound or a visual label.

3. The diagnostic test kit of claim 1, wherein the first specific binding member, the second specific binding member, the first receptive material, and the second receptive material are immunoreactive binding members.

4. The diagnostic test kit of claim 1, wherein the calibration analyte and the test analyte are members of the same protein family.

5. The diagnostic test kit of claim 1, wherein the test analyte is a pentraxin protein.

6. The diagnostic test kit of claim 5, wherein the test analyte is C-reactive protein.

7. The diagnostic test kit of claim 5, wherein the calibration analyte is a pentraxin protein.

8. The diagnostic test kit of claim 7, wherein the calibration analyte is a phosphocholine-binding pentraxin protein.

9. The diagnostic test kit of claim 8, wherein the calibration analyte is pentraxin 3, neuronal pentraxin 1, or neuronal pentraxin 2.

10. The diagnostic test kit of claim 1, wherein the calibration analyte and the test analyte are members of different protein families.

11. The diagnostic test kit of claim 1, wherein the first specific binding member is configured to bind to the test analyte and the second specific binding member is configured to bind to the calibration analyte.

12. The diagnostic test kit of claim 11, wherein the first receptive material is configured to bind to the test analyte to form a sandwich complex, and the second receptive material is configured to bind to the calibration analyte to form a sandwich complex.

13. The diagnostic test kit of claim 11, wherein the first receptive material and test analyte are configured to compete for binding with the first specific binding member, and the second receptive material and calibration analyte are configured to compete for binding with the second specific binding member.

14. The diagnostic test kit of claim 1, wherein the first specific binding member and the test analyte are configured to compete for binding with the first receptive material, and the second specific binding member and the calibration analyte are configured to compete for binding with the second receptive material.

15. The diagnostic test kit of claim 1, wherein the calibration zone is located downstream from the detection zone.

16. The diagnostic test kit of claim 1, wherein the lateral flow assay device further comprises a conjugate pad in fluid communication with the porous membrane, wherein one or more of the assay reagents are disposed on the conjugate pad.

17. The diagnostic test kit of claim 16, wherein the detection probes and calibration probes are disposed on the conjugate pad.

18. The diagnostic test kit of claim 16, further comprising a sample pad that is positioned upstream from the conjugate pad and defines a point of application for the test sample, wherein the calibration analyte is disposed on the sample pad.

19. The diagnostic test kit of claim 1, wherein the detection zone is capable of producing a detection signal and the calibration zone is capable of producing a calibration signal, wherein the intensity of the detection signal, as calibrated by the intensity of the calibration signal, is directly or indirectly proportional to the concentration of the test analyte within the test sample.

20. The diagnostic test kit of claim 1, wherein one or more of the assay reagents are disposed on the lateral flow device at a location that is downstream from a point of application for the test sample.

21. The diagnostic test kit of claim 1, wherein one or more of the assay reagents are disposed on the lateral flow device at a location that is upstream from a point of application for the test sample.

22. A method for quantitatively or semi-quantitatively detecting a test analyte within a test sample using a lateral flow device, the device comprising a porous membrane in communication with detection probes conjugated with a first specific binding member and calibration probes conjugated with a second specific binding member, the porous membrane defining a detection zone and a calibration zone, the method comprising:

i) contacting the lateral flow device with a calibration analyte;

ii) contacting the lateral flow device with the test sample;

iii) measuring the intensity of a detection signal produced at the detection zone; and

iv) measuring the intensity of a calibration signal produced at the calibration zone, wherein the amount of the test analyte is proportional to the intensity of the detection signal as calibrated by the intensity of the calibration signal.

23. The method of claim 22, wherein the amount of the test analyte is directly proportional to the intensity of the detection signal as calibrated by the intensity of the calibration signal.

24. The method of claim 22, wherein the amount of the test analyte is inversely proportional to the intensity of the detection signal as calibrated by the intensity of the calibration signal.

25. The method of claim 22, further comprising mixing the calibration analyte with the test sample prior to contact with the lateral flow device.

26. The method of claim 22, further comprising generating a calibration curve by plotting the ratio of the detection signal intensity to the calibration signal intensity for a plurality of predetermined analyte concentrations.

27. A method for quantitatively or semi-quantitatively detecting a test analyte within a test sample using a lateral flow device, the device comprising a porous membrane in communication with a calibration analyte, detection probes conjugated with a first specific binding member and calibration probes conjugated with a second specific binding member, the porous membrane defining a detection zone and a calibration zone, the method comprising:

i) contacting the lateral flow device with the test sample;

ii) measuring the intensity of a detection signal produced at the detection zone; and

iii) measuring the intensity of a calibration signal produced at the calibration zone, wherein the amount of the test analyte is proportional to the intensity of the detection signal as calibrated by the intensity of the calibration signal.

28. The method of claim 27, wherein the amount of the test analyte is directly proportional to the intensity of the detection signal as calibrated by the intensity of the calibration signal.

29. The method of claim 27, wherein the amount of the test analyte is inversely proportional to the intensity of the detection signal as calibrated by the intensity of the calibration signal.

30. The method of claim 27, further comprising generating a calibration curve by plotting the ratio of the detection signal intensity to the calibration signal intensity for a plurality of predetermined analyte concentrations.