Monitoring an Immunoassay

• US 20100206055A1
• Filed: 06/19/2008
• Published: 08/19/2010
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: Alere Toxicology Plc (Abbott Laboratories)
• Original Assignee: Concateno UK Limited (Abbott Laboratories)
• Inventors: Brookes, David Patrick Edward, Abbott, Timothy John
• Granted Patent: US 9,360,478 B2
• Time in Patent Office: Days
• US Class Current: 73/53.10
• CPC Class Codes: G01N 11/02 by measuring flow of the material
• CPC Class Codes: G01N 33/54306 Solid-phase reaction mechanisms
• 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

Abstract

A method of monitoring an immunoassay comprises determining the position of the flow edge of fluid across an immunoassay region. This allows, for example, early detection of possible errors in the test. For example the speed of the movement of the fluid flow edge may be determined from measurements of the position of the fluid flow edge at times throughout the test, and the determined speed may be compared with one or more thresholds to determine whether the test is proceeding correctly. A further method of monitoring an immunoassay comprising monitoring the variation with time of a reference zone of an immunoassay region. This can provide the user with early information as to whether the test is proceeding correctly. The above methods may also be used to provide methods to improve the run conditions of a test during its development. The method may be applied to a competitive assay.

Claims

1. A method of monitoring the quality of an immunoassay, the method comprising determining the position of the flow edge of fluid across an immunoassay region;

determining a value of a parameter representing variation with time of the position of the flow edge of fluid across the immunoassay region; and

obtaining information about the quality of the immunoassay from the value of the parameter.

2. A method as claimed in claim 1 and comprising obtaining a correction for the performance of the test from the determined value of the parameter.

3. A method as claimed in claim 1 and comprising comparing the determined value of the parameter with a reference.

4. A method as claimed in claim 3 and comprising taking at least one environmental factor into account in the step of comparing the determined value of the parameter with the reference.

5. A method as claimed in claim 4 wherein the at least one environmental factor comprises the ambient temperature.

6. A method as claimed in claim 4 wherein the at least one environmental factor comprises the ambient humidity.

7. A method as claimed in claim 4, wherein the at least one environmental factor comprises the tilt of the immunoassay region.

8. A method as claimed in claim 2 and comprising obtaining the correction using a look-up table.

9. A method as claimed in claim 1 wherein the parameter is selected from the group consisting of:

a time before movement of the flow edge of fluid is detected, a speed of movement of the fluid flow edge, a change in speed of movement of the fluid flow edge and a time for the fluid flow edge to cross the immunoassay region.

10. A method as claimed in claim 1 and comprising the step of determining a start of movement of the flow edge of fluid across the immunoassay region.

11. A method as claimed in claim 1 and further including the step of determining when the flow edge of fluid reaches a boundary of an active area of the immunoassay region.

12. A method as claimed in claim 10 and comprising taking the observed time for the fluid flow edge to reach the boundary into account in the determination of an incubation period for the immunoassay.

13. A method as claimed in claim 1 and further comprising monitoring the shape of the flow edge of fluid.

14. A method as claimed in claim 1 and comprising monitoring the variation with time of the area of the immunoassay region containing fluid.

15. A method as claimed in claim 1 and further comprising determining the position of the flow edge of fluid across another immunoassay region.

16. A method as claimed in claim 15 and comprising comparing the speed of movement of the fluid flow edge across the immunoassay region with the speed of movement of the fluid flow edge across the another immunoassay region.

17. A method as claimed in claim 15 and comprising comparing the travel time of the fluid flow edge across the immunoassay region with the travel time of the fluid flow edge across the another immunoassay region.

22. An immunoassay reader adapted to perform a method as defined in claim 1.

18. A method of monitoring an immunoassay, the method comprising monitoring the shape of the flow edge of fluid across an immunoassay region.

19. A method as claimed in claim 18 and comprising comparing the determined shape of the flow edge of fluid with a reference shape.

20. A method of monitoring the quality of an immunoassay, the method comprising monitoring the variation with time of a reference zone of an immunoassay region.

21. A method as claimed in claim 20 and comprising comparing a determined parameter of the reference zone with a predetermined threshold.