Systems and methods for non-fasting LDL cholesterol assays

Patent metadata

Field	Value
Publication number	US-9207184-B2
Application number	US-201313874971-A
Country	US
Kind code	B2
Filing date	May 1, 2013
Priority date	May 4, 2012
Publication date	Dec 8, 2015
Grant date	Dec 8, 2015

Abstract

In one embodiment, a test strip for testing for cholesterol-related blood analytes in whole blood includes a red blood cell separation layer, the red blood cell separation layer separating red blood cells from a blood sample applied to the test strip as the blood sample flows downward through the red blood cell separation layer. The test strip further includes a reaction layer receiving the blood sample from the red blood cell separation layer, the reaction layer including POE-POP-POE block copolymer, a surfactant, and a reflectivity changing reactant, the POE-POP-POE block copolymers solubilizing essentially only non-LDL cholesterol analytes, the non-LDL cholesterol analytes reacting with the reflectivity changing reactant in order to change a reflectivity of the blood sample.

First claim

What is claimed as new and desired to be protected by Letters Patent of the United States is:

1. A test strip for testing for cholesterol-related blood analytes in whole blood, the test strip comprising:
a red blood cell separation layer, the red blood cell separation layer separating red blood cells from a blood sample applied to the test strip as the blood sample flows downward through the red blood cell separation layer; and
a reaction layer receiving the blood sample from the red blood cell separation layer, the reaction layer including POE-POP-POE block copolymer, a surfactant, and a reflectivity changing reactant, the POE-POP-POE block copolymers solubilizing essentially only non-LDL cholesterol analytes, the non-LDL cholesterol analytes reacting with the reflectivity changing reactant in order to change a reflectivity of the blood sample.

2. The test strip of claim 1 , further comprising a spreading layer, oriented on top of the red blood cell separation layer.

3. The test strip of claim 1 where the POE-POP-POE block copolymer is selected from the list of copolymers consisting of a copolymer having a MW 3800, and a formula POE 7 -POP 54 -POE 7 ; a copolymer having a MW 4400, and a formula POE 5 -POP 68 -POE 5 ; a copolymer having a MW 5750, and a formula POE 20 -POP 70 -POE 20 ; and a copolymer having a MW 12600; and a formula POE 106 -POP 70 -POE 106 .

4. The test strip of claim 3 , further comprising a secondary blood separation layer adjacent to the red blood cell separation layer, the secondary blood separation layer separating additional red blood cells from the blood sample.

5. The test strip of claim 4 where the secondary blood separation layer further includes dextran sulfate.

6. The test strip of claim 5 where a molecular weight of the dextran sulfate is between 10K and 1000K.

7. The test strip of claim 5 where a molecular weight of the dextran sulfate is between 50k and 750K.

8. The test strip of claim 6 where a molecular weight of the dextran sulfate is 500K.

9. The test strip of claim 1 where the POE-POP-POE block copolymer is a copolymer having a MW 5750; and a formula POE 20 -POP 70 -POE 20 .

10. The test strip of claim 9 where a ratio of POE-POP-POE block copolymer to surfactant is 10 parts POE-POP-POE block copolymer to one part surfactant.

11. The test strip of claim 10 where a pH of the reaction layer is at least 5.4.

12. The test strip of claim 10 where a pH of the reaction layer is at least 6.8.

13. The test strip of claim 10 where a pH of the reaction layer is at least 7.4.

14. The test strip of claim 11 where a pH of the reaction layer is 6.8.

15. The test strip of claim 1 where the blood separation layer includes D-23 borosilicate glass fiber impregnated with Phaselous Vulgaris (PHA-P) Lectins.

16. A method of determining concentration of non-LDL cholesterol in a whole blood sample using a dry phase test strip, the method comprising:
contacting the whole blood sample with a blood separation layer of the test strip;
separating blood cells from the whole blood sample producing plasma;
flowing the plasma through the blood separation layer to a test layer;
reacting a non-LDL fraction in preference to an LDL fraction through the addition of a POE-POP-POE block copolymer to the test layer;
producing a color in the test layer substantially in proportion to a concentration of the non-LDL fraction in the sample; and
measuring the color produced.

17. A test strip for determining the concentration of LDL cholesterol in a sample of whole blood comprising:
a test matrix having at least two stacks, a first stack of the at least two stacks for total cholesterol and a second stack of the at least two stacks for non-LDL;
the first stack having reagents incorporated therein to produce a colorimetric response in proportion to the amount of total cholesterol in the samples; and
the second stack having reagents incorporated therein to produce a colorimetric response in proportion to the amount of non-LDL cholesterol in the sample, wherein the second stack includes a POE-POP-POE block copolymer,
the test strip configured to be read by a test meter, the test meter obtaining a value of non-LDL cholesterol from the second stack and subtracting the value of non-LDL cholesterol from a value of total cholesterol obtained from the first stack to yield a value of LDL cholesterol in the sample.

18. A test strip and meter combination for determining the concentration of LDL cholesterol in a sample of whole blood comprising:
a test strip including:
a test matrix having at least two stacks, a first stack of the at least two stacks for total cholesterol and a second stack of the at least two stacks for non-LDL;
the first stack having reagents incorporated therein to produce a colorimetric response in proportion to the amount of total cholesterol in the samples; and
the second stack having reagents incorporated therein to produce a colorimetric response in proportion to the amount of non-LDL cholesterol in the sample, wherein the second stack includes a POE-POP-POE block copolymer; and

a test meter configured to read the test strip, the test meter configured to obtain a value of non-LDL cholesterol from the second stack and subtract the value of non-LDL cholesterol from a value of total cholesterol obtained from the first stack to yield a value of LDL cholesterol in the sample.

19. A method of measuring LDL cholesterol from a human subject providing a blood sample, the method comprising:
providing a dry test strip;
receiving the blood sample at the dry test strip;
separating red blood cells from the blood sample in a first layer of the dry test strip;
reacting non-LDL cholesterol in the blood sample in a reaction layer, wherein the reaction layer includes a POE-POP-POE block copolymer;
producing a color change proportional to the non-LDL cholesterol;
measuring the color change to determine a non-LDL cholesterol amount in the blood sample; and
subtracting the non-LDL cholesterol amount from a total cholesterol amount in the blood sample to yield an LDL cholesterol amount for the blood sample.

20. The method of claim 19 where the blood sample is from an individual who has not fasted and the resulting LDL cholesterol amount is more accurate than the Friedwald equation.

21. The method of claim 19 where the reaction layer further includes a surfactant, and a reflectivity changing reactant, wherein the reacting includes solubilizing essentially only cholesterol from non-LDL analytes, the cholesterol from non-LDL analytes reacting with the reflectivity changing reactant in order to change a reflectivity of the blood sample.

22. The method of claim 21 where the POE-POP-POE block copolymer is selected from the list of copolymers consisting of a copolymer having a MW 3800, and a formula POE 7 -POP 54 -POE 7 ; a copolymer having a MW 4400, and a formula POE 5 -POP 68 -P 0 E 5 ; a copolymer having a MW 5750, and a formula POE 20 -POP70-POE 20 ; and a copolymer having a MW 12600; and a formula POE 106 -POP 70 -POE 106 .

23. The method of claim 21 , further comprising:
spreading the blood sample with a spreading layer, oriented on top of the first layer.

24. The method of claim 23 , further comprising:
reacting the blood sample in a total cholesterol reaction layer, the total cholesterol reaction layer oriented to receive a portion of the blood sample from the spreading layer;
producing a color change proporti

Assignees

• Polymer Technology Systems Inc

Inventors

• Riley Timothy
• Patwardhan Aniruddha
• Laduca Frank

Classifications

• G01N33/92 Primary

  involving lipids, e.g. cholesterol {, lipoproteins, or their receptors (steroid hormones G01N33/743)} · CPC title

• G01N2021/7759

  Dipstick; Test strip · CPC title

• G01N33/48

  Biological material, e.g. blood, urine (G01N33/02, G01N33/26, G01N33/44, G01N33/46 take precedence); Haemocytometers (counting blood corpuscules distributed over a surface by scanning the surface G06M11/02) · CPC title

• G01N21/78 Primary

  producing a change of colour · CPC title

• G01N33/525

  Multi-layer analytical elements · CPC title