Reduction of the hook effect in assay devices

• US 20040197820A1
• Filed: 04/03/2003
• Published: 10/07/2004
• Est. Priority Date: 04/03/2003
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Wei, Ning, Yang, Kaiyuan, Huang, Yanbin
• Granted Patent: US 7,851,209 B2
• Time in Patent Office: Days
• US Class Current: 435/7.1
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G01N 33/587 Nanoparticles

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 conjugated probes that contain a specific binding member for the analyte of interest. The specific binding member preferentially complexes with the analyte within a test sample when contacted therewith. Excess analyte that remains uncomplexed with the specific binding member undergoes non-specific binding, such as to a hydrophobic domain. As a result, the ability of the uncomplexed analyte to compete with the complexed analyte at the detection zone of the device is restricted. Thus, the incidence of “false negatives” is limited in a simple, efficient, and relatively inexpensive manner.

Claims

1. 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 in communication with detection probes capable of generating a detection signal, said detection probes being conjugated with a specific binding member for the analyte, said porous membrane defining a detection zone within which a receptive material is immobilized;

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

iii) allowing said uncomplexed analyte to undergo non-specific binding; and

iv) forming ternary complexes between said analyte/probe complexes and said receptive material within said detection zone, wherein said receptive material remains relatively free of said uncomplexed analyte.

2. A method as defined in claim 1, wherein said uncomplexed analyte non-specifically binds to a domain present on at least a portion of said conjugated detection probes.

3. A method as defined in claim 2, wherein said conjugated detection probes containing said domain individually define a hollow interior constituting from about 20% to about 100% of the spatial volume occupied by said probe, said probes having an interior surface and an exterior surface.

4. A method as defined in claim 3, wherein said interior surface includes said domain.

5. A method as defined in claim 3, wherein said conjugated detection probes have a spherical shape.

6. A method as defined in claim 3, wherein said conjugated detection probes are formed from a core polymer and a shell polymer.

7. A method as defined in claim 3, wherein said conjugated detection probes are formed by electrostatic layer deposition.

8. A method as defined in claim 2, wherein said domain is hydrophobic.

9. A method as defined in claim 1, wherein said conjugated detection probes define pores that have an average size less than about 100 nanometers.

10. A method as defined in claim 1, wherein the average size of said conjugated detection probes ranges from about 0.1 nanometers to about 100 microns.

11. A method 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.

12. 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 in communication with detection probes capable of generating a detection signal, said detection probes being conjugated with a specific binding member for the analyte and individually defining a hollow interior constituting from about 20% to about 100% of the spatial volume occupied by said probe, said probes having an interior surface and an exterior surface, said porous membrane defining a detection zone within which a receptive material is immobilized;

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

iii) allowing said uncomplexed analyte to non-specifically bind to said interior surface of said conjugated detection probes; and

iv) forming ternary complexes between said analyte/probe complexes and said receptive material within said detection zone, wherein said receptive material remains relatively free from said uncomplexed analyte.

13. A method as defined in claim 12, wherein at least a portion of said interior surface is hydrophobic.

14. A method as defined in claim 12, wherein said conjugated detection probes define pores that have an average size less than about 100 nanometers.

15. A method as defined in claim 12, wherein said conjugated detection probes have a spherical shape.

16. A method as defined in claim 12, wherein said conjugated detection probes are formed from a core polymer and a shell polymer.

17. A method as defined in claim 12, wherein said conjugated detection probes are formed by electrostatic layer deposition.

18. A method as defined in claim 12, wherein the average size of said conjugated detection probes ranges from about 0.1 nanometers to about 100 microns.

19. 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 in communication with detection probes capable of generating a detection signal, said detection probes being conjugated with a specific binding member for the analyte and 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 conjugated detection probes further containing a domain capable of non-specifically binding to said uncomplexed analyte, said porous membrane defining a detection zone within which a receptive material is immobilized that is configured to bind to said analyte/probe complexes, wherein said conjugated detection probes are capable of generating a detection signal while within said detection zone so that the amount of the analyte within the test sample is determined from said detection signal.

20. A flow-through assay device as defined in claim 19, wherein said conjugated detection probes containing said domain individually define a hollow interior constituting from about 20% to about 100% of the spatial volume occupied by said probe, said probes having an interior surface and an exterior surface.

21. A flow-through assay device as defined in claim 20, wherein said interior surface includes said domain.

22. A flow-through assay device as defined in claim 20, wherein said conjugated detection probes have a spherical shape.

23. A flow-through assay device as defined in claim 20, wherein said conjugated detection probes are formed from a core polymer and a shell polymer.

24. A flow-through assay device as defined in claim 20, wherein said conjugated detection probes are formed by electrostatic layer deposition.

25. A flow-through assay device as defined in claim 19, wherein said domain is hydrophobic.

26. A flow-through assay device as defined in claim 19, wherein said conjugated detection probes define pores that have an average size less than about 100 nanometers.

27. A flow-through assay device as defined in claim 19, wherein the average size of said conjugated detection probes ranges from about 0.1 nanometers to about 100 microns.

28. A flow-through assay device as defined in claim 19, 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.