Method for extending the dynamic detection range of assay devices

• US 7,781,172 B2
• Filed: 11/21/2003
• Issued: 08/24/2010
• Est. Priority Date: 11/21/2003
• Status: Expired due to Fees

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Song, Xuedong
• Primary Examiner(s): Gabel; Gailene R
• Assistant Examiner(s): DIRAMIO, JACQUELINE A
• Application Number:
  US10/719,976
• Publication Number:
  US 20050112780A1
• Time in Patent Office: 2,468 Days
• Field of Search: 422/50, 422/55, 422/56, 422/58, 422/61, 422/68.1, 435/4, 435/7.1, 435/287.1, 435/287.2, 435/287.7, 435/288.7, 436/501, 436/518, 436/528, 436/530
• US Class Current: 435/7.1
• CPC Class Codes: B64D 45/0053 using visual equipment, e.g. cameras
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• 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: G07C 5/085 using electronic data carriers
• CPC Class Codes: G07C 5/0883 wherein the data carrier is removable
• CPC Class Codes: G07C 5/0891 Video recorder in combination with video camera
• CPC Class Codes: G08B 13/19634 Electrical details of the system, e.g. component blocks for carrying out specific functions
• CPC Class Codes: G08B 13/19641 Multiple cameras having overlapping views on a single scene
• CPC Class Codes: G08B 13/1965 the vehicle being an aircraft
• CPC Class Codes: G08B 13/19656 Network used to communicate with a camera, e.g. WAN, LAN, Internet
• CPC Class Codes: G08B 13/19663 Surveillance related processing done local to the camera
• CPC Class Codes: G08B 13/19669 Event triggers storage or change of storage policy

Abstract

A flow-through assay device for detecting the presence or quantity of an analyte residing in a test sample is provided. The device utilizes a detection zone and compensation zone within which are immobilized capture reagents. The present inventor has discovered that the presence of a compensation zone may enable the detection of an analyte over extended concentration ranges. In particular, the compensation zone facilitates the binding of probes that would otherwise bind within the interior of assay device or that would exhibit “self-quenching”.

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 detection probes and calibration probes, said detection probes having a net charge and being conjugated with a specific binding member for the analyte, said porous membrane defining:

a detection zone within which is immobilized a first capture reagent, said first capture reagent being configured to bind to at least a portion of said conjugated detection probes or complexes formed between the analyte and said conjugated detection probes to generate a detection signal having an intensity;

a compensation zone located downstream from said detection zone, wherein a polyelectrolyte is immobilized within said compensation zone, said polyelectrolyte having a net charge opposite to that of the detection probes, said polyelectrolyte being configured to bind to said conjugated detection probes and complexes formed between the analyte and said conjugated detection probes passing through said detection zone to generate a compensation signal having an intensity, wherein the intensity of said compensation signal is inversely proportional to the intensity of said detection signal; and

a calibration zone within which a second capture reagent is immobilized, said second capture reagent being configured to bind to said calibration probes to generate a calibration signal that is substantially constant in intensity relative to the intensities of said detection signal and said compensation signal, said calibration zone being positioned between said detection zone and said compensation zone;

wherein the amount of the analyte within the test sample is proportional to the ratio of said detection signal intensity to said compensation signal intensity, as calibrated by said calibration signal intensity.

2. 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, luminescent compounds, radioactive compounds, visual labels, liposomes, and combinations thereof.

3. A flow-through assay device as defined in claim 1, wherein said conjugated detection probes comprise a luminescent compound.

4. A flow-through assay device as defined in claim 1, wherein said conjugated detection probes comprise a visual label.

5. A flow-through assay device as defined in claim 1, wherein said specific binding member is selected from the group consisting of antigens, haptens, aptamers, primary or secondary antibodies, biotin, and combinations thereof.

6. A flow-through assay device as defined in claim 1, wherein said first capture reagent is selected from the group consisting of antigens, haptens, protein A or G, neutravidin, avidin, streptavidin, captavidin, primary or secondary antibodies, and complexes thereof.

7. A flow-through assay device as defined in claim 1, wherein said polyelectrolyte has a net positive charge.

8. A flow-through assay device as defined in claim 7, wherein said polyelectrolyte is selected from the group consisting of polylysine, polyethyleneimine, epichlorohydrin-functionalized polyamines or polyamidoamines, polydiallyldimethyl-ammonium chloride, cationic cellulose derivatives, and combinations thereof.

9. A flow-through assay device as defined in claim 1, wherein said polyelectrolyte has a net negative charge.

10. A flow-through assay device as defined in claim 1, wherein said second capture reagent comprises antigens, haptens, protein A or G, neutravidin, avidin, streptavidin, captavidin, primary or secondary antibodies, or complexes thereof.

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

12. A flow-through assay device as defined in claim 1, wherein the polyelectrolyte is ionically bonded to a functional group present on the surface of the porous membrane.

13. A flow-through assay device as defined in claim 1, wherein the polyelectrolyte is covalently bonded to a functional group present on the surface of the porous membrane.

14. A flow-through assay device as defined in claim 13, wherein the polyelectrolyte is crosslinked to the functional group.

15. A flow-through assay device as defined in claim 1, wherein the detection probes comprise latex microparticles.

16. A flow-through assay device as defined in claim 1, wherein the compensation zone is generally free of biological capture reagents.

17. A flow-through assay device as defined in claim 1, wherein said specific binding member includes an antibody.

18. A flow-through assay device as defined in claim 17, wherein said first capture reagent includes an antibody.