Method for detection of an analyte

• US 6,475,805 B1
• Filed: 04/04/2000
• Issued: 11/05/2002
• Est. Priority Date: 12/31/1997
• Status: Expired due to Term

• Current Assignee: Charm Sciences, Inc.
• Original Assignee: Charm Sciences, Inc.
• Inventors: Markovsky, Robert J., Charm, Stanley E., Saul, Steven J., Zomer, Eliezer, Skiffington, Richard
• Primary Examiner(s): Nguyen, Bao-Thuy L.
• Application Number:
  US09/542,203
• Time in Patent Office: 945 Days
• Field of Search: 422/56, 422/58, 422/187, 422/188, 422/104, 422/110, 435/7.1, 435/7.2, 435/7.8, 435/7.92, 435/7.94, 435/7.95, 435/174, 435/287, 435/970, 435/971, 435/7.93, 436/518, 436/524, 436/538, 436/530, 436/535, 436/533, 436/810, 436/807
• US Class Current: 436/514
• CPC Class Codes: G01N 33/537 with separation of immune complex from unbound antigen or antibody
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 435/971 Capture of complex after antigen-antibody reaction
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

A test device, system and method, the device composed of an elongated, toothbrush-shaped, transparent, plastic housing and a lateral-flow test strip for the detection of an analyte, such as a beta-lactam in milk, in the housing, the housing having an expansion cavity to receive expanded, liquid-contacted, absorbing material in the test strip, and to control lateral flow rate and times in the test strip.

Claims

1. A method for the detection of an analyte or analyte class in a liquid sample, comprising the steps of:

a) providing a lateral flow test strip within a housing, wherein a portion of the housing defines an expansion housing cavity, and wherein the test strip comprises (i) a first end, a second end, a top surface, and a bottom surface, (ii) an absorption zone proximal to the first end, the absorption zone comprising an expandable absorption material within the expansion housing cavity defined by said housing, the expansion housing cavity dimensioned to prevent full expansion of the absorption material, and (iii) a reference zone comprising one or more component(s) for detection of said analyte or analyte class;

b) allowing a contact to form between the test strip and the liquid sample so as to allow absorption of the liquid sample into the absorption material, thereby causing the absorption material to expand within the expansion housing cavity so as to aid in forcing the liquid-sample to flow toward the reference zone; and

c) observing changes in the reference zone as an indication of the presence or absence of the analyte or analyte class in the liquid sample.

2. The method of claim 1, wherein said test strip further comprises a disposal zone between the reference zone and the second end.

3. The method of claim 1, wherein the shape of said absorption material generally mimics two dimensions of the expansion cavity.

4. The method of claim 1, wherein the absorption material is positioned on the top surface of the test strip.

5. The method of claim 4, wherein one side of the expansion housing cavity can be opened to expose the bottom surface of the test strip.

6. The method of claim 1, wherein said contacting comprises dipping the absorption material into a source of the liquid sample.

7. The method of claim 1, further comprising the step of incubating the test strip with the liquid sample thereon.

8. The method of claim 1, wherein the housing comprises an aperture, and said method further comprises allowing air to exit the housing through the aperture.

9. The method of claim 1, wherein at least a portion of said housing is substantially transparent.

10. The method of claim 1, wherein the housing comprises a peelable seal, and said contacting comprises peeling said seal from said housing.

11. The method of claim 1, wherein said expansion housing cavity has a volume, the volume of said expansion housing cavity preventing said absorption material from expanding to more than eighty percent (80%) of its full expansion volume.

12. The method of claim 11, wherein the volume of the expansion housing cavity prevents said absorption material from expanding to more than fifty percent (50%) of its full expansion volume.

13. The method of claim 1, wherein said analyte class is a class of antibiotics.

14. The method of claim 1, wherein said liquid sample is a biological fluid.

15. The method of claim 1, wherein said observing comprises determining whether said analyte or analyte class is present in said liquid sample at or above a threshold concentration.

16. The method of claim 1, wherein said contacting comprises allowing absorption of the liquid sample in a preselected amount.

17. The method of claim 1, wherein the absorption material is a filter.

18. The method of claim 1, wherein the liquid sample comprises milk.

19. The method of claim 1, wherein the analyte comprises beta lactams.

20. The method of claim 1, wherein expansion of the absorption material is restricted by contact with a wall of the expansion housing cavity so as to control the volume of the liquid sample flowing to the reference zone.

21. The method of claim 1, wherein full expansion of the absorption material is restricted by a top internal wall of the expansion housing cavity.

22. The method of claim 1, wherein said housing comprises a blister package.

23. A method for the detection of an analyte or analyte class in a liquid sample, comprising the steps of:

a) providing a lateral-flow test strip within a housing, the test strip comprising (i) a first end, a second end, a top surface, and a bottom surface, (ii) an absorption zone proximal to the first end, the absorption zone comprising an expandable absorption material positioned on the top surface of the test strip within an expansion cavity, the expansion cavity dimensioned to prevent full expansion of the absorption material and having one side that can be opened to expose the bottom surface of the test strip, and (iii) a reference zone comprising one or more component(s) for detection of said analyte or analyte class;

b) allowing a contact to form between the test strip and the liquid sample so as to allow absorption of the liquid sample into the absorption material, thereby causing the absorption material to expand within the expansion cavity so as to force the liquid-sample to flow toward the reference zone; and

c) observing changes in the reference zone as an indication of the presence or absence of the analyte or analyte class in the liquid sample.

24. A method for the detection of an analyte or analyte class in a liquid sample, comprising the steps of:

a) providing a lateral-flow test strip within a housing, the test strip comprising (i) a first end, a second end, a top surface, and a bottom surface, (ii) an absorption zone proximal to the first end, the absorption zone comprising an expandable absorption material within an expansion cavity portion of said housing, the expansion cavity dimensioned to prevent full expansion of the absorption material, and (iii) a reference zone comprising one or more component(s) for detection of said analyte or analyte class;

b) allowing a contact to form between the test strip and the liquid sample so as to allow absorption of the liquid sample into the absorption material, thereby causing the absorption material to expand within the expansion cavity so as to force the liquid-sample to flow toward the reference zone, wherein the housing comprises a peelable seal and said contacting comprises peeling said seal from said housing; and

c) observing changes in the reference zone as an indication of the presence or absence of the analyte or analyte class in the liquid sample.

25. A sethod for the detection of an analyte or analyte class in a liquid sample, comprising the steps of:

a) providing a lateral-flow test strip within a housing, the test strip comprising (i) a first end, a second end, a top surface, and a bottom surface, (ii) an absorption zone proximal to the first end, the absorption zone comprising an expandable absorption material within an expansion cavity portion of said housing, the expansion cavity having a volume and dimensioned to prevent full expansion of the absorption material, and (iii) a reference zone comprising one or more component(s) for detection of said analyte or analyte class;

b) allowing a contact to form between the test strip and the liquid-sample so as to allow absorption of the liquid sample into the absorption material, the volume of the expansion cavity preventing said absorption material from expanding to more than eighty percent (80%) of its full volume thereby causing the absorption material to expand within the expansion cavity so as to force the liquid-sample to flow toward the reference zone; and

c) observing changes in the reference zone as an indication of the presence or absence of the analyte or analyte class in the liquid sample.

26. The method of claim 25, wherein the volume of the expansion cavity prevents said absorption material from expanding to more than fifty percent (50%) of its full expansion volume.

27. The method of claim 25, wherein the volume of the expansion cavity prevents said absorption material from expanding to more than sixty percent (60%) of its full expansion volume.

28. The method of claim 25, wherein the volume of the expansion cavity prevents said absorption material from expanding to more than thirty percent (30%) of its full expansion volume.