Diagnostic sanitary test strip

• US 6,040,195 A
• Filed: 06/10/1997
• Issued: 03/21/2000
• 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:
  US08/872,088
• Time in Patent Office: 1,015 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 for measuring an analyte of interest in a heterogenous fluid sample, said test strip comprising:

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

(b) means for retaining the fluid sample to prevent spillage of the sample from said strip to make said test strip sanitary, wherein said retaining means comprises a plurality of dam partitions penetrating said test strip, said dam partitions being defined by indentations formed in said upper layer;

(c) means, in vertical alignment and contiguous contact with said sample receiving port, for uniformly spreading the fluid sample in said receiving port before allowing said fluid sample to vertically pass through said spreading means;

(d) means, in contiguous contact with said spreading means, for filtering the fluid sample received from said spreading means to remove at least one undesirable element in the fluid sample prior to passing the fluid sample through said filtering means;

(e) a reaction membrane, in contiguous contact with said filtering means, having a predetermined porosity, said membrane retaining a reagent solution capable of reacting with the analyte of interest to produce a color change in said membrane corresponding to the amount of analyte present in the fluid sample; and

(f) a lower support layer in contiguous contact with said membrane and having a reaction viewing port in vertical alignment with said membrane for displaying said color change, wherein said retaining means, said spreading means, said filtering means, and said reaction membrane interpose said lower support and said upper support to secure said test strip.

2. The test strip of claim 1, wherein said dam partitions are oriented around said receiving port.

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

4. The test strip of claim 3, wherein said reagent solution includes an enzyme solution.

5. The test strip of claim 3, wherein said reagent solution in said filtering means comprises a red blood cell binding agent for capturing red blood cells from the fluid sample.

6. The test strip of claim 3, wherein said red blood cell binding agent comprises lectins.

7. The test strip of claim 1, wherein said reagent solution in said filtering means is capable of detecting glucose analytes in the fluid sample.

8. The test strip of claim 7, wherein said reagent solution in said filtering means includes an indicator chemical capable of visually indicating the amount of glucose analytes in the fluid sample.

9. The test strip of claim 1, wherein said filtering means comprises a separating layer having a plurality mesh openings and being treated with a chemical solution capable of capturing said undesirable element for filtering the fluid sample prior to passing the fluid sample through said mesh openings.

10. The test strip of claim 5, 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 membrane comprises an isotropic membrane such that said membrane has a substantially uniform porosity.

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

13. The test strip device of claim 1, wherein said upper layer comprises a plurality of detents for mating with securing posts in a corresponding reflectance meter.

14. The test strip of claim 1, wherein said reagent solution in said filtering means is capable of detecting cholesterol analytes in the fluid sample.

15. The test strip of claim 1, wherein said reagent solution in said filtering means is capable of detecting osteoporosis analytes in the fluid sample.

16. The test strip of claim 1, wherein said reagent solution in said filtering means is capable of detecting ketones analytes in the fluid sample.

17. The test strip of claim 1, wherein said reagent solution in said filtering means is capable of detecting theophylline analytes in the fluid sample.

18. The test strip of claim 1, wherein said reagent solution in said filtering means is capable of detecting H1AC analytes in the fluid sample.

19. The test strip of claim 1, further comprising means for properly orienting said test strip in a corresponding meter.

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

21. A diagnostic sanitary test strip device for measuring an analyte of interest in a heterogenous fluid sample, said test strip comprising:

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

(b) means for retaining the fluid sample to prevent spillage of the sample from said strip to make said test strip sanitary;

(c) means, in vertical alignment and contiguous contact with said sample receiving port, for uniformly spreading the fluid sample in said receiving port before allowing said fluid sample to vertically pass through said spreading means;

(d) means, in contiguous contact with said spreading means, for filtering the fluid sample received from said spreading means to remove at least one undesirable element in the fluid sample prior to passing the fluid sample through said filtering means;

(e) a reaction membrane, in contiguous contact with said filtering means, having a predetermined porosity, said membrane retaining a reagent solution capable of reacting with the analyte of interest to produce a color change in said membrane corresponding to the amount of analyte present in the fluid sample;

(f) a lower support layer in contiguous contact with said membrane and having a reaction viewing port in vertical alignment with said membrane for displaying said color change, wherein said retaining means, said spreading means, said filtering means, and said reaction membrane interpose said lower support and said upper support to secure said test strip; and

(g) a means for properly orienting said test strip in a corresponding meter located on an upper surface of said support layer.

22. The test strip of claim 21, wherein said orienting means comprises a light absorption medium on an exposed surface of said upper layer.

23. A diagnostic sanitary test strip device for measuring an analyte of interest in a heterogenous fluid sample, said test strip comprising:

(a) an upper support layer defining a sample receiving port for receiving the fluid sample therein and a plurality of detents for mating with securing posts in a corresponding reflectance meter;

(b) means for retaining the fluid sample to prevent spillage of the sample from said strip to make said test strip sanitary;

(c) means, in vertical alignment and contiguous contact with said sample receiving port, for uniformly spreading the fluid sample in said receiving port before allowing said fluid sample to vertically pass through said spreading means;

(d) means, in contiguous contact with said spreading means, for filtering the fluid sample received from said spreading means to remove at least one undesirable element in the fluid sample prior to passing the fluid sample through said filtering means;

(e) a reaction membrane, in contiguous contact with said filtering means, having a predetermined porosity, said membrane retaining a reagent solution capable of reacting with the analyte of interest to produce a color change in said membrane corresponding to the amount of analyte present in the fluid sample; and

(f) a lower support layer in contiguous contact with said membrane and having a reaction viewing port in vertical alignment with said membrane for displaying said color change, wherein said retaining means, said spreading means, said filtering means, and said reaction membrane interpose said lower support and said upper support to secure said test strip.