Opaque reaction matrix for the analysis of the whole blood

• US 5,968,765 A
• Filed: 10/31/1997
• Issued: 10/19/1999
• Est. Priority Date: 11/08/1996
• Status: Expired due to Fees

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Mercury Diagnostics, Inc.
• Inventors: Lee, Pat S., Grage, Henry M., Douglas, Joel S.
• Primary Examiner(s): Leary, Louise N.
• Application Number:
  US08/961,942
• Time in Patent Office: 718 Days
• Field of Search: 435/25, 435/14, 435/2, 435/4, 435/970, 435/968
• US Class Current: 435/25
• CPC Class Codes: B01D 69/141 Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
• CPC Class Codes: C12Q 1/26 involving oxidoreductase
• CPC Class Codes: C12Q 1/54 involving glucose or galactose
• CPC Class Codes: G01N 33/5002 Partitioning blood components
• CPC Class Codes: G01N 33/52 Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72
• CPC Class Codes: G01N 33/521 Single-layer analytical elements
• CPC Class Codes: Y10S 435/968 High energy substrates, e.g. fluorescent, chemiluminescent, radioactive
• CPC Class Codes: Y10S 435/97 Test strip or test slide

Abstract

A test strip for use in determining the presence or concentration of an analyte in whole blood is disclosed. The test strip is a porous membrane having disposed thereon (a) a separating agent capable of separating from whole blood, red blood cells and a fluid component substantially free of red blood cells; (b) an indicating reagent system capable of indicating the presence or concentration of an analyte in the fluid component by producing a spectrophotometric change upon contact with the fluid component; and (c) an opaque filler capable of reducing spectrophotometric interference caused by the presence of the red blood cells. Also disclosed are methods of testing whole blood for the presence or concentration of an analyte using the test strip.

Claims

1. A test strip for use in determining the presence or concentration of an analyte in whole blood, said test strip comprising a porous membrane having disposed thereon (a) a separating agent capable of separating from whole blood, red blood cells and a fluid component substantially free of red blood cells;

(b) an indicating reagent system capable of indicating the presence or concentration of an analyte in the fluid component by producing a spectrophotometric change upon contact with the fluid component, said indicating reagent system comprising 3-methyl-6-(M sulfonate)-benzothiazolinone-(2)-hydrazone, where M is sodium, potassium or ammonium; and

(c) an opaque filler capable of reducing spectrophotometric interference caused by the presence of the red blood cells.

2. The test strip of claim 1 wherein the porous membrane is selected from the group consisting of a polyethersulfone membrane, a polysulfone membrane and a nylon membrane.

3. The test strip of claim 1 wherein the porous membrane is a polyethersulfone membrane.

4. The test strip of claim 2 wherein the membrane is from about 0.002 to about 0.20 inches in thickness and has a mean pore size of about 0.1 to about 1 micron.

5. The test strip of claim 4 wherein the membrane is cast with a skin structure on one side and is isotropic through the remaining thickness of the membrane.

6. The test strip of claim 1 wherein the separating agent is selected from the group consisting of polyvinyl sulfonic acid, polyethylene glycol, polystyrene sulfonic acid, hydroxypropyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, citrates, formates, sulfates, amino acids, chitosan, citric acid, phytic acid, malic acid and mixtures thereof.

7. The test strip of claim 6 wherein the separating agent is distributed homogeneously within the membrane.

8. The test strip of claim 6 wherein the separating agent is coated on the surface of the membrane.

9. The test strip of claim 6 wherein the separating agent forms an interior layer within the membrane.

10. The test strip of claim 1 wherein the opaque finer is selected from the group consisting of titanium dioxide, lime stone dust, plastic beads, talcum powder, calcium powder and mixtures thereof.

11. The test strip of claim 10 wherein the opaque filer is titanium dioxide.

12. The test strip of claim 10 wherein the opaque filler is distributed homogeneously within the membrane.

13. The test strip of claim 10 wherein the opaque filler is coated on the surface of the membrane.

14. The test strip of claim 10 wherein the opaque filler forms an interior layer within the membrane.

15. The test strip of claim 1 wherein the indicating reagent system comprises a glucose oxidase.

17. The method of claim 1 wherein the reading or measurement is provided by an instrument.

18. The method of claim 1 wherein the reading or measurement is provided visually.

19. The method of claim 1 wherein the porous membrane is selected from the group consisting of a polyethersulfone membrane, a polysulfone membrane and a nylon membrane.

20. The method of claim 19 wherein the porous membrane is a polyethersulfone membrane.

21. The method of claim 19 wherein the membrane is from about 0.002 to about 0.20 inches in thickness and has a mean pore size of about 0.1 to about 1 micron.

22. The method of claim 21 wherein the membrane is cast with a skin structure on one side and is isotropic through the remaining thickness of the membrane.

16. A method of testing whole blood for the presence or concentration of an analyte comprising:

(a) providing a test strip comprising a porous membrane having disposed thereon (i) a separating agent capable of separating from whole blood, red blood cells and a fluid component substantially free of red blood cells;

(ii) an indicating reagent system capable of indicating the presence or concentration of an analyte in the fluid component by producing a spectrophotometric change upon contact with the fluid component, said indicating reagent system comprising 3-methyl-6-(M sulfonate)-benzothiazolinone-(2)-hydrazone, where M is sodium, potassium or ammonium; and

(iii) an opaque filler capable of reducing spectrophotometric interference caused by the presence of the red blood cells;

(b) applying a whole blood sample to a first side of the test strip; and

(c) reading or measuring on a second side of the test strip a spectrophotometric change in the fluid component to determine the presence or concentration of the analyte.

23. The method of claim 16 wherein the separating agent is selected from the group consisting of polyvinyl sulfonic acid, polyethylene glycol, polystyrene sulfonic acid, hydroxypropyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, citrates, formates, sulfates, amino acids, chitosan, citric acid, phytic acid, malic acid and mixtures thereof.

24. The method of claim 23 wherein the separating agent is distributed homogeneously within the membrane.

25. The method of claim 23 wherein the separating agent is coated on the surface of the membrane.

26. The method of claim 23 wherein the separating agent forms an interior layer within the membrane.

27. The method of claim 16 wherein the opaque filler is selected from the group consisting of titanium dioxide, lime stone dust, plastic beads, talcum powder, calcium powder and mixtures thereof.

28. The method of claim 27 wherein the opaque filler is titanium dioxide.

29. The method of claim 27 wherein the opaque filler is distributed homogeneously within the membrane.

30. The method of claim 27 wherein the opaque filler is coated on the surface of the membrane.

31. The method of claim 27 wherein the opaque filler forms an interior layer within the membrane.

32. The method of claim 16 wherein the indicating reagent system comprises a glucose oxidase.