Diagnostic sanitary test strip

• US 6,284,550 B1
• Filed: 06/25/1999
• Issued: 09/04/2001
• Est. Priority Date: 06/10/1997
• Status: Expired due to Fees

• Current Assignee: Nipro Diagnostics, Inc.
• Original Assignee: Home Diagnostics Incorporated
• Inventors: Bell, Douglas E., Schneider, Jon, Carroll, Patrick
• Primary Examiner(s): Chin, Christopher L.
• Application Number:
  US09/344,895
• Time in Patent Office: 802 Days
• Field of Search: 422/55-58, 422/61, 435/11, 435/14, 435/174, 435/180, 435/287.1, 435/287.2, 435/287.7, 435/287.8, 435/287.9, 435/805, 435/810, 435/970, 436/66, 436/71, 436/164, 436/169, 436/170, 436/514, 436/518, 436/531, 436/805, 436/810, 436/815, 436/827
• US Class Current: 436/514
• CPC Class Codes: G01N 33/525 Multi-layer analytical elements
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/81 Packaged device or kit
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick
• CPC Class Codes: Y10S 436/815 Test for named compound or class of compounds
• CPC Class Codes: Y10S 436/827 Lectins

Abstract

An improved multi-layered diagnostic sanitary test strip for receiving a heterogenous fluid, such as whole blood, to test for presence and/or amount of a suspected analyte in the fluid by facilitating a color change in the strip corresponding to the amount of the analyte in the fluid, wherein the test strip includes fluid volume control dams to prevent spillage of the fluid from the strip and a chemical reagent solution that facilitates end-point testing. The improved test strip comprises (a) an upper support strip having a fluid receiving port and (b) a lower support strip having a color change viewing port and securely sandwiched therebetween (c) a spreading mesh screen for uniformly distributing the fluid, (d) a chemically treated separating layer for removing an undesirable element, e.g. red blood cells, from the fluid received from the mesh screen, (e) an isotropic membrane chemically treated with a reagent indicator solution for removing any remaining portions of the undesirable element, producing a color change proportionate to the amount of the suspected analyte in the fluid and facilitating an end-point ramp test, and (f) volume control dam partitions for retaining fluid on and in the strip.

Claims

1. A diagnostic sanitary test strip device having a unitary construction for measuring an analyte of interest in a heterogeneous fluid sample, said test strip comprising:

(a) a reaction membrane containing a reagent capable of reacting with the analyte of interest to produce a measurable change in said membrane;

(b) an upper support layer defining a sample receiving port for receiving the fluid sample thereat;

(c) one or more structures for directing the sample containing the analyte of interest through at least a portion of said reaction membrane; and

(d) a lower support layer having a reaction viewing port in vertical alignment with said membrane for displaying said measurable change, said lower support being associated with said upper support to secure said reaction membrane in said test strip.

2. The test strip of claim 1, further comprising a plurality of dam partitions defined by indentations formed in said upper support layer.

3. The test strip of claim 2, wherein said dam partitions are oriented around said receiving port.

4. The test strip of claim 1, wherein said reagent comprises reactants that facilitate an end-point test in a corresponding reflectance meter.

5. The test strip of claim 4, wherein said reagent includes an enzyme solution.

6. The test strip of claim 1, wherein said reagent in said reaction membrane comprises a red blood cell binding agent for capturing red blood cells from the fluid sample.

7. The test strip of claim 6, wherein said red blood cell binding agent comprises lectins.

8. The test strip of claim 1, wherein said reagent in said reaction membrane is capable of detecting glucose analytes in the fluid sample.

9. The test strip of claim 7, wherein said reagent in said reaction membrane includes an indicator chemical capable of visually indicating the amount of glucose analytes in the fluid sample.

10. The test strip of claim 1, wherein the mesh openings in said separating layer are smaller than said mesh openings in said spreading screen.

11. The test strip of claim 1, wherein said reaction membrane comprises an isotropic membrane such that said membrane has a substantially uniform porosity.

12. The test strip of claim 11, wherein said membrane comprises a material containing polysulfone.

13. The test strip of claim 2 wherein said upper support layer comprises at least one detent for mating with securing posts in a corresponding reflectance meter.

14. The test strip of claim 2, wherein said reagent in said reaction membrane is capable of detecting cholesterol analytes in the fluid sample.

15. The test strip of claim 2, wherein said reagent in said reaction membrane is capable of detecting osteoporosis analytes in the fluid sample.

16. The test strip of claim 2, wherein said reagent in said reaction membrane is capable of detecting ketones analytes in the fluid sample.

17. The test strip of claim 2, wherein said reagent in said reaction membrane is capable of detecting theophylline analytes in the fluid sample.

18. The test strip of claim 2, wherein said reagent in said reaction membrane is capable of detecting H1AC analytes in the fluid sample.

19. The test strip of claim 2, further comprising indicia of proper orientation and insertion of said test strip in a corresponding meter.

20. The test strip of claim 19, wherein said indicia comprises a light absorption medium on an exposed surface of said upper support layer.

21. The test strip of claim 1, wherein said measurable change in said reagent corresponds to the amount of analyte of interest present.

22. The test strip of claim 1, further comprising:

(d) a spreading screen, in vertical alignment and contiguous contact with said sample receiving port, for receiving said sample containing an analyte of interest, said spreading screen having mesh openings of a predetermined size sufficient to facilitate uniform distribution of said sample over said screen in the area of said receiving port before allowing said sample to vertically pass through said mesh openings.

23. The test strip of claim 22, further comprising:

(e) a separating layer, in contiguous contact with said spreading screen, for receiving the sample containing the analyte of interest from said spreading screen, said separating layer having mesh openings and being treated with a chemical solution for separating at least one undesirable element from the fluid sample prior to passing the fluid sample through said mesh openings.

24. The test strip of claim 2, wherein said reagent in said reaction membrane is capable of detecting fructosamine analytes in the fluid sample.

25. The test strip of claim 19, wherein said indicia comprises an arrow on said upper support layer to indicate proper direction of insertion.

26. The test strip of claim 22, wherein said spreading screen is pre-treated with a reagent capable of reacting with the analyte of interest to produce a measurable change in said membrane.

27. The test strip of claim 22, wherein said separating layer is pre-treated with a reagent capable of reacting with the analyte of interest to produce a measurable change in said membrane.

28. The test strip of claim 2 wherein said dam partitions comprise four dam partitions positioned approximately 90°

apart around a sample receiving port.

29. The test strip of claim 28 wherein said sample receiving port is substantially circular.