Direct measurement of chlolesterol from low density lipoprotein with test strip

• US 7,435,577 B2
• Filed: 10/11/2004
• Issued: 10/14/2008
• 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: Lawrence, Gregory M., Pasqua, John
• Primary Examiner(s): Weber; Jon P
• Assistant Examiner(s): Shen; Bin
• Application Number:
  US10/962,272
• Publication Number:
  US 20050170447A1
• Time in Patent Office: 1,464 Days
• Field of Search: None
• US Class Current: 435/287.7
• 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

Cholesterol from Low Density Lipoproteins (LDL-C) is measured directly with a test strip at room temperature using a reagent that takes advantage of the varying surface charge density on LDLs and non-LDLs to selectively make LDL-C available for testing.

Claims

1. A vertical flow test strip for use in the direct detection of cholesterol produced from low density lipoprotiens in a whole blood, plasma or serum sample, the test strip comprising:

a) a red blood cell blocking membrane for blocking or slowing the progress of red blood cells through the test strip;

b) a cholesterol detection membrane for providing a color change in the presence of cholesterol; and

c) in said test strip between said red blood cell membrane and said cholesterol detection membrane, a supply of combination of reagents that can bind with non-LDL lipoproteins to block the cholesterol in said non-LDL lipoprotiens fromb eing measured in said chloesterol detection membrane while selectively permitting low density lipoprotein cholesterol (LDL-C) to be directly measured.

2. The test strip of claim 1, wherein said combination of reagents are selected fromthe group consisting of cations, polyanions, cyclodextrin derivatives, a copolymeric surfactant and a surfactant for the coplymeric surfactant.

3. The test strip of claim 2, wherein the cations include a divalent metal.

4. The test strip of claim 3, wherein the divalent metal is magnesium.

5. The test strip of claim 2, wherein the cations include a postiviely charged amine effective to bind lipoproteins.

6. The test strip of claim 5, wherein the amine is triethanolamine hydrochloride.

7. The test strip of claim 2, wherein the polyanion is dextran sulfate.

8. The test strip of claim 2, wherein the cyclodextrin derivative is alpha cyclodextrin sulfate.

9. The test strip of claim 2 wherein the copolymeric surfactant is a polyoxyethylene-polyoxypropylene-polyoxyethylene hybrid, having a molecular weight range from about 2,100 to about 6,000 with a preponderance of polyoxyethylene.

10. The test strip of claim1, wherein the reagents include a high molecular wieght blocking copolymer surfactant effective to bind non-LDLs and a low molecular weight surfactant effective to increase the solubility of the blocking copolymer surfactant.

11. The test strip of claim 1, wherein said red blood cell blocking membrane is impregnated with at least some of the supply of a combination of reatgents.

12. The test strip of claim 1, further comprising at least one intermediate membrane impregnated with at least some of the supply of a combination of reagents.

13. A vertical flow test strip for use in the direct detection of cholesterol produced from low density lipoproteins in a whole blood, plasma or serum sample, the test strip comprising:

(a) a red blood cell blocking membrane for blocking or slowing the progress of red blood cells through the test strip;

(b) a cholesterol detection membrane for providing a color change in the presence of cholesterol; and

(c) a supply of a combination of reagents in said test strip that block the enzymatic conversion of non-LDL lipoproteins and permitting the conversion of LDL-C lipoprotien cholesterol.

14. a test strip as in claim 13 wherein said test strip functions at room temperature.

15. A test strip as inclaim 13 wherein said combination of reagents includes block copolymer surfactants.

16. A test strip as in claim 15 wherein said combination of reagents includes lower molecular weight surfactants that increase the solubility of said block copolymer surfactants.

17. A test strip as in claim 13, further comprising triblock copolymer and surfactants inpregnated adjacent to said cholesterol detection membrane.

18. A test strip as in cliam 13, further comprising triblock copolymer and surfactants impregnated in said cholesterol detection membrane.