Non-precipitating bodily fluid analysis system

• US 20060063267A1
• Filed: 08/17/2005
• Published: 03/23/2006
• Est. Priority Date: 02/03/2004
• Status: Active Grant

• Current Assignee: Polymer Technology Systems Incorporated (Sinocare, Inc.)
• Original Assignee: Polymer Technology Systems Incorporated (Sinocare, Inc.)
• Inventors: Knight, Meredith, Lawrence, Gregory M.
• Granted Patent: US 7,625,721 B2
• Time in Patent Office: Days
• US Class Current: 436/71
• CPC Class Codes: G01N 2021/8494 Measuring or storing parameters of the band
• CPC Class Codes: G01N 2021/8654 Mechanical support; Mounting of sheet
• CPC Class Codes: G01N 21/78 producing a change of colour
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04
• CPC Class Codes: G01N 2201/0221 Portable; cableless; compact; hand-held
• CPC Class Codes: G01N 2800/044 Hyperlipemia or hypolipemia, e.g. dyslipidaemia, obesity
• CPC Class Codes: G01N 33/526 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/92 involving lipids, e.g. cholesterol , lipoproteins, or their receptors steroid hormones G01N33/743

Abstract

A bodily fluid analyzer including a dry test strip impregnated with a reagent providing a non-precipitating reaction to exclude non-desired analytes. The reagent complexes the non-desired analytes so they remain in solution but cannot participate in the test reaction. Red blood cells are removed from the detection area by slowing their vertical movement and stopping flow when the detection membrane is saturated.

Claims

1. A method of determining a characteristic of a selected one of a plurality of analytes in a bodily fluid, said method comprising:

providing said bodily fluid containing said selected analyte and one or more non-selected analytes;

applying said bodily fluid to a dry test strip; and

reacting said selected one of said analytes with a reactant in said dry test strip to provide an indication of said characteristic while preventing said one or more non-selected analytes from participating in said reaction, without precipitating said one or more non-selected analytes.

2. A method as in claim 1 wherein said bodily fluid is blood.

3. A method as in claim 2 wherein said selected analyte is high density lipoprotein (HDL).

4. A method as in claim 3 wherein said characteristic comprises the concentration of said high density lipoproteins in said blood.

5. A method as in claim 2 wherein said one or more non-selected analytes are selected from the group consisting of HDL, analytes, such as LDL (low density lipoproteins), VLDL (very low density lipoproteins), ILDL (intermediate density lipoproteins), and chylomicrons (big, tryglyceride-rich lipoproteins).

6. A method as in claim 2 wherein said selected analyte is low density lipoprotein (LDL).

7. A method as in claim 6 wherein said characteristic comprises the concentration of said low density lipoproteins in said blood.

8. A method as in claim 1 wherein said indication is an optical indication.

9. A method as in claim 8 wherein said optical indication is a colorimetric indication.

10. A method as in claim 1 wherein said preventing comprises complexing said non-selected analyte so that it cannot participate in said reaction.

11. A method as in claim 10 wherein said complexing comprises interacting said non-selected analytes with a polyanion.

12. A method as in claim 11 wherein said polyanion is an anionic polymer.

13. A method as in claim 12 wherein said anionic polymer has a molecular weight between 50,000 and 8,000.

14. A method as in claim 12 wherein said anionic polymer has a molecular weight between 25,000 and 10,000.

15. A method as in claim 12 wherein said anionic polymer has a molecular weight between 18,000 and 12,000.

16. A method as in claim 12 wherein said anionic polymer comprises dextran sulphate.

17. A method as in claim 12 wherein said reacting further comprises reacting with a divalent metal.

18. A method as in claim 10 wherein said complexing comprises exposing said non-selected analyte to a reagent comprising dextran sulphate and a divalent metal.

19. A method as in claim 10 wherein said selected analyte is LDL and said complexing comprises exposing said bodily fluid to a reagent comprising dextran sulphate, a divalent metal;

and wherein said method further comprises exposing said LDL to a destabilizing compound.

20. A method as in claim 19 wherein said destabilizing compound is selected from the group consisting of glycols, polypropylenes, and polyethylenes.

21. A method as in claim 1 wherein said preventing further comprises flowing said complexed non-selected analytes through an asymmetric membrane to slow their flow.

22. A dry test strip for determining a characteristic of a selected analyte in blood, said dry test strip comprising:

a reaction layer including chemicals that will react with said blood to provide a characteristic of a selected analyte in said blood; and

said dry test strip further containing a complexing chemical that complexes non-selected analytes to prevent them from participating in said reaction without precipitating them.

23. A dry test strip as in claim 22 wherein said complexing chemical comprises a polyanion.

24. A dry test strip as in claim 23 wherein said polyanion is an anionic polymer.

25. A dry test strip as in claim 24 wherein said anionic polymer has a molecular weight between 50,000 and 8,000.

26. A dry test strip as in claim 24 wherein said anionic polymer has a molecular weight between 25,000 and 10,000.

27. A dry test strip as in claim 24 wherein said anionic polymer has a molecular weight between 18,000 and 12,000.

28. A dry test strip as in claim 24 wherein said anionic polymer comprises dextran sulphate.

29. A dry test strip as in claim 22 wherein said complexing chemical further comprises a divalent metal.

30. A dry test strip as in claim 22 wherein said dry test strip further includes a compound that is destabilizing to said selected analyte.

31. A method as in claim 30 wherein said destabilizing compound is selected from the group consisting of glycols, polypropylenes, and polyethylenes.

32. A dry test strip as in claim 22 and further comprising a blood separation layer designed to slow or stop red blood cells from reaching said reaction layer.