Apparatus and methods for analyte measurement immunoassay

• US 8,642,322 B2
• Filed: 04/12/2013
• Issued: 02/04/2014
• Est. Priority Date: 03/05/2002
• Status: Expired due to Term

• Current Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Davis, Graham, Lin, Chao, Miller, Cary James, Lauks, Imants
• Primary Examiner(s): BROWN, MELANIE YU
• Application Number:
  US13/861,794
• Publication Number:
  US 20130224775A1
• Time in Patent Office: 298 Days
• Field of Search: 435/7.1, 435/283.1, 435/285.2, 435/288.5, 435/287.1, 435/287.2, 436/518
• US Class Current: 435/288.5
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2300/0663 Whole sensors
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2400/0421 electrophoretic flow
• CPC Class Codes: B01L 2400/046 Chemical or electrochemical formation of bubbles
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 2400/0683 mechanically breaking a wall or membrane within a channel or chamber
• CPC Class Codes: B01L 3/502723 characterised by venting arrangements
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: G01N 2035/0436 with pre-packaged reagents, i.e. test-packs
• CPC Class Codes: G01N 33/543 with an insoluble carrier for immobilising immunochemicals
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 35/08 using a stream of discrete samples flowing along a tube system, e.g. flow injection analysis

Abstract

The present invention relates to methods for measuring an amount of an analyte using an electrochemical assay in a conduit comprising a sensor, wherein said sensor comprises an electrode having a surface layer of immobilized antibody that binds said analyte, and a counter/reference electrode disposed within said conduit. A solution comprising a substrate for said enzyme and at least one air segment contacts the sensor to remove unbound analyte and labeled antibody from a region of the sensor. The disclosed invention is adaptable to the point-of-care clinical diagnostic field, including use in accident sites, emergency rooms, surgery, nursing homes, intensive care units, and non-medical environments.

Claims

1. A method of measuring an amount of an analyte in a sample, the method comprising:

displacing the sample from a sample inlet to a first conduit comprising a sensor;

contacting the sample with the sensor;

contacting an enzyme-labeled antibody with the sensor, wherein the enzyme-labeled antibody is configured to bind the analyte in the sample;

displacing the sample from the sensor into a waste region;

providing a solution in a second conduit, wherein the solution comprises a substrate for the enzyme-labeled antibody;

displacing the solution from the second conduit into the first conduit, wherein the displacing the solution comprises forming at least one air segment in the solution;

contacting the solution and the at least one air segment with the sensor to remove unbound analyte and labeled antibody from a region of the sensor; and

detecting a product of a reaction between the enzyme-labeled antibody and the substrate using the sensor.

2. The method of claim 1, wherein the displacing the sample into the waste region closes a first vent.

3. The method of claim 2, wherein the forming the at least one air segment comprises forcing air through a second vent into the first conduit.

4. The method of claim 2, wherein the closing the first vent prevents the first vent from venting excess pressure and subsequently displacing the sample back into the first conduit.

5. The method of claim 2, wherein:

the displacing the solution further comprises actuation of a pump to create a lower pressure in the first conduit, the lower pressure draws the solution from the second conduit through a capillary stop and into the first conduit; and

the actuation of the pump occurs subsequent to the closing the first vent.

6. The method of claim 3, wherein:

the second vent comprises a membrane that vibrates as the air is forced through the second vent providing an intermittent air stream; and

the intermittent air stream interrupts the displacing the solution from the second conduit into the first conduit, and causes the forming the at least one air segment.

7. The method of claim 1, further comprising displacing the solution and the at least one air segment from the sensor towards the sample inlet such that only a thin layer of the solution remains on the sensor.

8. The method of claim 1, wherein the sample comprises the enzyme-labeled antibody dissolved therein.

9. The method of claim 1, wherein the contacting the enzyme-labeled antibody with the sensor occurs subsequent to the contacting the sample with the sensor and prior to the contacting the solution and the at least one air segment with the sensor.