Accessible assay and method of use

• US 7,323,139 B2
• Filed: 04/24/2003
• Issued: 01/29/2008
• Est. Priority Date: 07/26/2002
• Status: Active Grant

• Current Assignee: Quantum Design International, Inc.
• Original Assignee: Quantum Design, Inc.
• Inventors: Taff, Randall N., Pratt, David M., LaBorde, Ronald T.
• Primary Examiner(s): Soderquist; Arlen
• Application Number:
  US10/422,336
• Publication Number:
  US 20040214347A1
• Time in Patent Office: 1,741 Days
• Field of Search: 422 56- 58, 436/58, 436/149, 436/177, 436525-526, 436/824
• US Class Current: 422/422
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]

Abstract

An assay test strip and cassette. The test strip is positioned in a housing shaped and configured to allow a detector to access the test strip from the side, rather than from the lengthwise axis of the test strip. The housing may contain one or more test strips which may also be disposed on one or more surfaces of the housing. Preferably, the housing is generally C-shaped with the test strip spanning the space between the two arms of the C-shape. The housing is sealed to protect both the operator and instrument from possible contamination. The test strip is preferably embedded with paramagnetic particles and process chemistry specific for a particular application. Quantitative analysis may be accomplished using a magnetic reader device. In additional embodiments, detection is accomplished by visual means.

Claims

1. A lateral flow assay test device for detection of target analytes in a sample, said device comprising:

a housing member shaped and configured to have two arms connected by a spanning portion, thereby generally forming an open space between the two arms, the housing also having an interior space exposed on one side of the housing;

a cover element shaped and configured to enclose the interior space of the housing member;

at least one analytical test strip having first and second ends and being positioned between the two arms, the strip also being at least partially sandwiched between the housing member and the cover element, the strip comprising;

a base member;

an analytical membrane having a first end and a second end;

a conjugate pad at the first end of the analytical membrane; and

at least one capture region in the analytical membrane intermediate said first and second ends thereof, said capture region being configured to capture labeled analytes moving from said first end of said analytical membrane toward said second end of said analytical membrane;

the open space in the housing member being shaped and configured to provide lateral access to the test strip and to enable the determination of the presence of target analytes in the capture region of the test strip while the test strip remains mounted to the housing.

2. The device of claim 1, further comprising a sample receiving element at the first end of The analytical membrane.

3. The device of claim 1, wherein The open space in the housing member is shaped and configured to provide lateral access to the test strip to enable a magnetic reader device to determine The presence and quantity of magnetic conjugate particle labeled analytes in the capture region of the test strip while The test strip remains mounted to the housing.

4. The device of claim 3, and further comprising a protective membrane covering said analytical membrane and a backing member on the side opposite to said protective membrane, said protective membrane also being optically non-transparent.

5. The device of claim 4, wherein said protective membrane is formed integrally with said analytical membrane.

6. The device of claim 4, and further comprising at least one magnetic calibration line printed on said protective membrane.

7. The device of claim 4, wherein said protective membrane is formed of material selected from the group consisting of plastic, glass and paper.

8. The device of claim 3, wherein said conjugate is disposed in a conjugate containing element that is in fluid flow contact with the first end of the analytical membrane.

9. The device of claim 3, wherein said conjugate further comprises superparamagnetic conjugate particles, said particles being configured to bind with target analytes in the sample.

10. The device of claim 1, and further comprising at least one control region in the analytical membrane intermediate said first and second ends thereof, said at least one control region being configured to collect conjugates that have passed the capture region to show that the test strip has been used.

11. The device of claim 1, and further comprising a wicking element at the second end of the analytical membrane.

12. The device of claim 1, wherein multiple analytical test strips are placed parallel between the two arms of the housing.

13. A lateral flow assay test device for detection of target analytes in a sample, said device comprising:

a housing member formed with two spaced arms defining an open space therebetween, the open space being externally accessible, the housing member having an interior space exposed on one side;

a cover element shaped and configured to enclose the interior space of the housing member; and

at least one elongated analytical test strip having first and second ends and being mounted to the housing, the ends of the test strip being partially sandwiched between the housing member and the cover at the two spaced arms thereby spanning the open space, the strip comprising;

a base member;

an analytical membrane having a first end and a second end;

a conjugate containing element in contact with the first end of the analytical membrane; and

at least one capture region in the analytical membrane intermediate said first and second ends thereof, said capture region being configured to capture conjugates moving from said first end of said analytical membrane toward said second end of said analytical membrane;

the open space in the housing member being shaped and configured to provide external access to the test strip from above, from below, and from the open space side to enable the determination of the presence of target analytes in the capture region of the test strip while the test strip remains mounted to the housing.

14. The device of claim 13, further comprising a sample receiving element at the first end of the analytical membrane.

15. The device of claim 14, and further comprising a wicking element at the second end of the analytical membrane, wherein the housing has cavities shaped and configured to accommodate the sample receiving element and the wicking element.

16. The device of claim 13, wherein the open space in the housing member is shaped and configured to provide lateral access to the test strip to enable a magnetic reader device to determine the presence and quantity of magnetic conjugate particle labeled analytes in the capture region of the test strip while the test strip remains mounted to the housing.

17. The device of claim 16, and further comprising a protective membrane covering said analytical membrane, and a backing member on the side opposite to said protective membrane, said protective membrane also being optically non-transparent.

18. The device of claim 17, and further comprising variable pressure pads located at the junction of the housing and the protective membrane on opposite sides of the open space.

19. The device of claim 18, and further comprising a sealant disposed on the housing at the junction of the housing and the protective membrane.

20. The device of claim 13, wherein the housing is square shaped and a test strip is positioned on at least one side thereof.

21. The device of claim 13, and further comprising a wicking element at the second end of the analytical membrane.

22. The device of claim 13, and further comprising a desiccant placed within the interior space of the housing.

23. The device of claim 13, and further comprising a label on the top surface of the housing.

24. The device of claim 16, wherein the test strip is thin enough to fit within about a 0.5 mm gap in the magnetic reader device.

25. The device of claim 13, wherein the test strip is tensioned along its lengthwise axis.

26. The device of claim 13, and further comprising a rigid removable cover placed over the at least one test strip that protects the test strip during storage and transport.