Assay device

• US 8,721,990 B2
• Filed: 04/09/2008
• Issued: 05/13/2014
• Est. Priority Date: 04/10/2007
• Status: Active Grant

• Current Assignee: Alere Switzerland GmbH (Abbott Laboratories)
• Original Assignee: Alere Switzerland GmbH (Abbott Laboratories)
• Inventors: Raj, Balbir, Eapen, Saji, Linley, Ezra
• Primary Examiner(s): WHITE, DENNIS MICHAEL
• Application Number:
  US12/595,741
• Publication Number:
  US 20100209297A1
• Time in Patent Office: 2,225 Days
• Field of Search: 422/400, 422/401, 422/420, 422/421, 422/422, 422/423, 422/424, 422/425, 422/426, 422/427, 422/428, 422/429, 422/68.1, 422/82.05, 422/82.06, 436/164, 436/169, 436/170, 435/13, 435/283.1, 435/287.1, 435/287.7, 435/287.8, 435/287.9, 435/288.7
• US Class Current: 422/420
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: C12Q 2537/125 Sandwich assay format
• 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: G01N 33/689 related to pregnancy or the gonads
• CPC Class Codes: G01N 33/76 Human chorionic gonadotropin including luteinising hormone, follicle stimulating hormone, thyroid stimulating hormone or their receptors
• CPC Class Codes: Y10T 29/494 Fluidic or fluid actuated device making

Abstract

Disclosed is an assay device for the determination of the presence and/or extent if an analyte in a liquid sample over an extended concentration range comprising a first assay and a second assay, wherein the first assay for an analyte comprises a first flow-path having a sole detection zone capable of immobilizing a labelled binding reagent and the second assay for said analyte comprises a second flow-path having a sole detection zone capable of immobilizing a labelled binding reagent, wherein the presence of labelled binding reagent at the detection zones provides an indication of the presence and/or extent of analyte in said liquid sample.

Claims

1. An assay device for the determination of hCG in a liquid sample over an extended concentration rang, comprising a first assay and a second assay,

wherein the first assay comprises a first flow-path having a sole first assay detection zone and a mobilisable, labeled, hCG-binding reagent provided upstream from the first assay detection zone;

and the second assay comprises a second flow-path having a sole second assay detection zone, a mobilisable, labeled, hCG-binding reagent provided upstream from the second assay detection zone, and a mobilisable scavenger binding reagent for hCG provided upstream from the second assay detection zone;

wherein the first and second assay detection zones each independently comprise an immobilised reagent that is capable of immobilising the respective labeled, hCG-binding reagent in the presence of hCG;

wherein said first and second assays are provided on separate substrates, or on a common substrate but with the first and second flow-paths fluidically isolated from one another;

wherein the immobilisation of the labeled, hCG-binding reagents at the detection zones provides an indication of hCG in said liquid sample; and

wherein the first assay provides an indication of hCG in a first concentration range and the second assay provides an indication of hCG in a second, higher concentration range.

2. The device according to claim 1 wherein the first and/or second flow-path comprises a porous carrier.

3. The device according to claim 2 wherein the porous carrier is a lateral flow porous carrier.

4. The device according to claim 1 wherein for the second assay, the scavenger binding reagent has a higher binding affinity for hCG than the mobilisable, labeled, hCG-binding reagent.

5. The device according to claim 1 wherein the mobilisable, labeled, hCG-binding reagent and the scavenger binding reagent of the second assay bind to respectively a first and second binding region of hCG, and the second assay detection zone comprises an immobilised binding reagent for a second binding region of hCG.

6. The device according to claim 1 wherein the mobilisable, labeled, binding reagent and the scavenger binding reagent of the second assay are provided in the same region.

7. The device according to claim 1 wherein the labelled binding reagent is labelled with an optically detectable particle.

8. The device according to claim 1, comprising a common porous sample receiver.

9. The assay device according to claim 1, wherein the first assay is a high sensitivity assay and the second assay is a low sensitivity hCG assay.

10. The device according to claim 1, comprising a housing wherein the first and second assays are provided within said housing.

11. The device according to claim 1 for the detection of hCG analyte in urine wherein the device comprises:

a) an illumination and detection means for illuminating and detecting labelled binding optical reagent at the detection zones;

b) a computation means for calculating a level of hCG or a value corresponding to the level of hCG;

c) a display means for displaying a result of the assay test;

d) a stored base threshold value, wherein a level of hCG corresponding to a value below the stored base threshold is indicative of being not pregnant and wherein a level of hCG corresponding to a value at or above the stored base threshold is indicative of being pregnant;

e) two further first and second stored threshold values wherein a level of hCG corresponding to a value less than or equal to a first threshold value is indicative of a level of pregnancy in a first range, a level of hCG corresponding to a value greater than the second threshold is indicative of a level of pregnancy in a third range, and a level of hCG corresponding to a value greater or equal to the first threshold but less than the second threshold is indicative of a level of hCG in a second range, wherein the display means is capable of indicating either a not pregnant condition, or a pregnant condition and the extent of pregnancy.

12. The device according to claim 1, wherein the scavenger binding reagent is unlabelled.

13. The device according to claim 1, wherein the scavenger binding reagent of the second assay is capable of binding to the beta subunit of hCG, and the mobilisable, labeled, hCG-binding reagent of the second assay is capable of binding to the alpha subunit of hCG.

14. The device according to claim 1, which is for the determination of the extent of pregnancy of a subject in time based units.

15. The device according to claim 14, wherein the extent of pregnancy is determined in units of weeks.

16. The device according to claim 14, wherein the determination of the extent of pregnancy is based upon stored reference values.

17. The device according to claim 1, wherein said extended concentration range is the range of about 10 to about 250,000 mIU/ml hCG.

18. The device according to claim 1, which does not contain more than two hCG assays.

19. The device according to claim 1, wherein the immobilised reagents in the first and second assay detection zones are immobilised hCG-binding reagents.

20. The device according to claim 19, wherein the immobilised reagents in the first and second assay detection zones are independently streptavidin or anti-biotin.

21. The device according to claim 1, wherein the first and second concentration ranges overlap.

22. A method of determining the extent of pregnancy in a pregnant woman subject, the method comprising the step of analysing a urine sample from the subject using an assay device in accordance with claim 1.

23. A method of determining pregnancy as well as the extent of pregnancy in a pregnant woman subject, the method comprising the step of analysing a urine sample from the subject using an assay device in accordance with claim 1.