Reduction of the hook effect in membrane-based assay devices

• US 20040121480A1
• Filed: 12/19/2002
• Published: 06/24/2004
• Est. Priority Date: 12/19/2002
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Wei, Ning, Huang, Yanbin
• Granted Patent: US 7,247,500 B2
• Time in Patent Office: Days
• US Class Current: 436/161
• CPC Class Codes: G01N 33/538 by sorbent column, particles or resin strip , i.e. sorbent materials
• CPC Class Codes: G01N 33/5432 Liposomes or microcapsules
• 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: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/809 Multifield plates or multicontainer arrays

Abstract

A membrane-based assay device for detecting the presence or quantity of an analyte residing in a test sample is provided. The device utilizes a chromatographic zone on which is disposed a plurality of microporous particles. The chromatographic zone can effectively reduce the “hook effect” in a simple, efficient, and relatively inexpensive manner. In particular, the plurality of microporous particles allows larger-sized analyte/probe complexes to reach the detection zone before the uncomplexed analyte. Because the uncomplexed analyte is substantially inhibited from competing with the complexes for the binding sites at the detection zone, the incidence of “false negatives” may be limited, even at relatively high analyte concentrations.

Claims

1. A flow-through assay device for detecting the presence or quantity of an analyte residing in a test sample, said flow-through assay device comprising a porous membrane, said porous membrane being in communication with conjugated detection probes capable of generating a detection signal, said porous membrane defining:

a chromatographic zone within which a plurality of microporous particles are immobilized; and

a detection zone located downstream from said chromatographic zone, wherein a capture reagent is immobilized within said detection zone that is configured to bind to said conjugated detection probes, wherein said conjugated detection probes are capable of generating a detection signal while within said detection zone, wherein the amount of the analyte within the test sample is determined from said detection signal.

2. A flow-through assay device as defined in claim 1, wherein said microporous particles define a plurality of spaces therebetween, said spaces having an average size that is greater than the average size of the micropores of said particles.

3. A flow-through assay device as defined in claim 1, wherein the average size of said micropores is at least about 100% less than the average size of said spaces.

4. A flow-through assay device as defined in claim 1, wherein the average size of said micropores is at least about 150% less than the average size of said spaces.

5. A flow-through assay device as defined in claim 1, wherein the average size of said micropores is at least about 250% less than the average size of said spaces.

6. A flow-through assay device as defined in claim 1, wherein the average size of said micropores is less than about 100 nanometers.

7. A flow-through assay device as defined in claim 1, wherein the average size of said micropores is from about 10 to about 60 nanometers.

8. A flow-through assay device as defined in claim 1, wherein said microporous particles are selected from the group consisting of polystyrenes, polyacrylamides, polyacrylonitriles, silica beads, and combinations thereof.

9. A flow-through assay device as defined in claim 1, wherein the surface of said microporous particles is chemically inert to the analyte.

10. A flow-through assay device as defined in claim 1, wherein said conjugated detection probes comprise a substance selected from the group consisting of chromogens, catalysts, fluorescent compounds, chemiluminescent compounds, phosphorescent compounds, radioactive compounds, direct visual labels, liposomes, and combinations thereof.

11. A flow-through assay device as defined in claim 1, wherein said porous membrane further comprises a calibration zone a capable of generating a calibration signal, wherein the amount of the analyte within the test sample is determined from said detection signal as calibrated by said calibration signal.

12. A flow-through assay device as defined in claim 11, wherein said porous membrane is in communication with calibration probes, said calibration probes generating said calibration signal when present within said calibration zone.

13. A flow-through assay device as defined in claim 1, wherein the device is a sandwich-type assay device.

14. A flow-through, sandwich assay device for detecting the presence or quantity of an analyte residing in a test sample, said assay device comprising a porous membrane, said porous membrane being in communication with conjugated detection probes capable of generating a detection signal, said conjugated detection probes being configured to combine with the analyte in the test sample when contacted therewith such that analyte/probe complexes and uncomplexed analyte are formed, said porous membrane defining:

a chromatographic zone within which a plurality of microporous particles are immobilized, said microporous particles being configured so that said uncomplexed analyte flows through said chromatographic zone at a slower rate than said analyte/probe complexes; and

a detection zone located downstream from said chromatographic zone, wherein a capture reagent is immobilized within said detection zone that is configured to bind to said analyte/probe complexes so that said complexes generate a detection signal while within said detection zone, wherein the amount of the analyte within the test sample is determined from said detection signal.

15. A flow-through, sandwich assay device as defined in claim 14, wherein said microporous particles define a plurality of spaces therebetween, said spaces having an average size that is greater than the average size of the micropores of said particles.

16. A flow-through, sandwich assay device as defined in claim 14, wherein the average size of said micropores is at least about 100% less than the average size of said spaces.

17. A flow-through, sandwich assay device as defined in claim 14, wherein the average size of said micropores is at least about 150% less than the average size of said spaces.

18. A flow-through, sandwich assay device as defined in claim 14, wherein the average size of said micropores is at least about 250% less than the average size of said spaces.

19. A flow-through, sandwich assay device as defined in claim 14, wherein said microporous particles are selected from the group consisting of polystyrenes, polyacrylamides, polyacrylonitriles, silica beads, and combinations thereof.

20. A flow-through, sandwich assay device as defined in claim 14, wherein the surface of said microporous particles are chemically inert to the analyte.

21. A flow-through, sandwich assay device as defined in claim 14, wherein said porous membrane further comprises a calibration zone a capable of generating a calibration signal, wherein the amount of the analyte within the test sample is determined from said detection signal as calibrated by said calibration signal.

22. A flow-through, sandwich assay device as defined in claim 21, wherein said porous membrane is in communication with calibration probes, said calibration probes generating said calibration signal when present within said calibration zone.

23. A method for detecting the presence or quantity of an analyte residing in a test sample, said method comprising:

i) providing a flow-through assay device comprising a porous membrane, said porous membrane being in communication with conjugated detection probes capable of generating a detection signal, said porous membrane defining a chromatographic zone within which a plurality of microporous particles are immobilized and a detection zone located downstream from said chromatographic zone, wherein a capture reagent is immobilized within said detection zone;

ii) contacting a test sample containing the analyte with said conjugated detection probes so that analyte/probe complexes and uncomplexed analyte are formed; and

iii) allowing said analyte/probe complexes and said uncomplexed analyte to reach said chromatographic zone and then said detection zone, wherein said analyte/probe complexes reach said detection zone before said uncomplexed analyte.

24. A method as defined in claim 23, wherein said microporous particles define a plurality of spaces therebetween, said spaces having an average size that is greater than the average size of the micropores of said particles.

25. A method as defined in claim 23, wherein the average size of said micropores is at least about 100% less than the average size of said spaces.

26. A method as defined in claim 23, wherein the average size of said micropores is at least about 150% less than the average size of said spaces.

27. A method as defined in claim 23, wherein the average size of said micropores is at least about 100% less than the average size of said spaces.

28. A method as defined in claim 23, wherein said microporous particles are selected from the group consisting of polystyrenes, polyacrylamides, polyacrylonitriles, silica beads, and combinations thereof.

29. A method as defined in claim 23, wherein the surface of said microporous particles is chemically inert to the analyte.

30. A method as defined in claim 23, further comprising measuring the intensity of the detection signal generated within said detection zone.

31. A method as defined in claim 23, wherein said porous membrane further comprises a calibration zone a capable of generating a calibration signal, wherein the amount of the analyte within the test sample is determined from said detection signal as calibrated by said calibration signal.

32. A method as defined in claim 31, wherein said porous membrane is in communication with calibration probes, said calibration probes generating said calibration signal when present within said calibration zone.

33. A method as defined in claim 32, further comprising generating a calibration curve by plotting the intensity of the detection signal calibrated by the intensity of the calibration signal for a plurality of predetermined analyte concentrations.