HDL Cholesterol Sensor Using Selective Surfactant

• US 20090130696A1
• Filed: 05/14/2007
• Published: 05/21/2009
• Est. Priority Date: 05/12/2006
• Status: Abandoned Application

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Orman, Howard, Burrows, Carla, Wilkinson, Katherine, Bayly, Simon, Askew, Herbert Frank, Murphy, Lindy
• Application Number:
  US12/298,881
• Publication Number:
  US 20090130696A1
• Time in Patent Office: Days
• US Class Current: 435/11
• CPC Class Codes: C12Q 1/60 involving cholesterol
• CPC Class Codes: G01N 33/92 involving lipids, e.g. cholesterol , lipoproteins, or their receptors steroid hormones G01N33/743

Abstract

A method for the determination of the amount of cholesterol in high density lipoproteins in a high density lipoprotein containing sample, said method comprising reacting the sample with a surfactant which preferentially reacts with high density lipoproteins in the sample, said surfactant being selected from hydroxyethyl glucamide derivatives and N-acyl-N-methyl glucamine derivatives, and measuring the amount of cholesterol in the high density lipoproteins, for example using an electrochemical technique.

Claims

1. A method for the determination of the amount of cholesterol in high density lipoproteins in a high density lipoprotein containing sample, said method comprising reacting the sample with (a) a surfactant which preferentially breaks down high density lipoproteins, said surfactant being selected from hydroxyethyl glucamide derivatives and N-acyl-N-methyl glucamine derivatives, and measuring the amount of cholesterol in the high density lipoproteins.

2. A method according to claim 1, wherein the surfactant is for improving the reproducibility of the determination of the amount of cholesterol in high density lipoproteins.

3. A method according to claim 1, wherein the surfactant (a) has a differentiation for HDL over LDL given by the equation (i) below of at least 50%:

4. A method according to claim 1, wherein the surfactant (a) is selected from HEGA-8, HEGA-9, HEGA-10, C-HEGA-9, C-HEGA-10, MEGA-8, MEGA-9, MEGA-10 and MEGA-12.

5. A method according to claim 1, wherein the method comprises repeating the measurement one or more times for a given sample to provide a data set of a plurality of measurements relating to the HDL concentration of the sample, and wherein R² for the data set is at least 0.6.

6. A method according to claim 1, wherein the amount of cholesterol in the high density lipoproteins is measured by reacting the sample with (b) a cholesterol ester hydrolysing reagent and (c) cholesterol oxidase or cholesterol dehydrogenase and determining the amount of cholesterol which has reacted with the cholesterol oxidase or cholesterol dehydrogenase.

7. A method according to claim 1, wherein the amount of cholesterol in the high density lipoproteins is measured by an electrochemical technique.

8. A method according to claim 7, wherein the method comprises reacting the sample with

(a) a surfactant which preferentially breaks down high density lipoproteins;

(b) a cholesterol ester hydrolysing reagent;

(c) cholesterol oxidase or cholesterol dehydrogenase;

(d) a coenzyme; and

(e) a redox agent capable of being oxidised or reduced to form a product;

and electrochemically detecting the amount of product formed.

9. A method according to claim 8, wherein the sample is additionally reacted with (f) a reductase.

10. A method according to claim 1, wherein the sample is reacted simultaneously with the surfactant (a), the cholesterol ester hydrolysing reagent (b) and the cholesterol oxidase or cholesterol dehydrogenase (c).

11. A method according to claim 1, wherein the high density lipoprotein containing sample is whole blood and wherein the method additionally comprises the step of filtering the sample to remove red blood cells.

12. A method according to claim 1, wherein the measurement of the amount of cholesterol in the high density lipoproteins is completed within a period of no more than 3 minutes from reaction of the sample with the surfactant.

13. A reagent mixture for use in a method for the determination of the amount of cholesterol in high density lipoproteins in a high density lipoprotein containing sample, the reagent mixture comprising

(a) a surfactant which preferentially breaks down high density lipoproteins, said surfactant being selected from hydroxyethyl glucamide derivatives and N-acyl-N-methyl glucamine derivatives;

(b) a cholesterol ester hydrolysing reagent; and

(c) cholesterol oxidase or cholesterol dehydrogenase.

14. A reagent mixture according to claim 13, which additionally comprises (d)

a coenzyme, (e) a redox agent capable of being oxidised or reduced to form a product;

and optionally (f) a reductase.

15. A kit for the determination of the amount of cholesterol in high density lipoproteins in a high density lipoprotein containing sample, the kit comprising (a) a surfactant which preferentially breaks down high density lipoproteins, said surfactant being selected from hydroxyethyl glucamide derivatives and N-acyl-N-methyl glucamine derivatives, (b) a cholesterol ester hydrolysing reagent, and (c) cholesterol oxidase or cholesterol dehydrogenase, and optionally one or more of (d) a coenzyme, (e) a redox agent capable of being oxidised or reduced to form a product, and (f) a reductase, and means for measuring the amount of cholesterol which reacts with the cholesterol oxidase or cholesterol dehydrogenase.

16. A kit according to claim 15 wherein the means for measuring the amount of cholesterol which reacts with the cholesterol oxidase or cholesterol dehydrogenase comprises

an electrochemical cell having a working electrode, a reference or pseudo reference electrode and optionally a separate counter electrode;

a power supply for applying a potential across the cell; and

a measuring instrument for measuring the resulting electrochemical response.

17. A kit according to claim 15, wherein the reagents (a), (b) and (c) and optionally one or more of (d), (e) and (f) are present in the form of a single reagent mixture.

18. A kit according to claim 17, wherein the reagent mixture is in dried form.

19. A method of operating a kit for the determination of the amount of cholesterol in high density lipoproteins in a high density lipoprotein containing sample, the kit comprising:

(a) a surfactant which preferentially breaks down high density lipoproteins, said surfactant being selected from hydroxyethyl glucamide derivatives and N-acyl-N-methyl glucamine derivatives, (b) a cholesterol ester hydrolysing reagent, and (c) cholesterol oxidase or cholesterol dehydrogenase, and optionally one or more of (d) a coenzyme, (e) a redox agent capable of being oxidised or reduced to form a product and (f) a reductase;

and means for measuring the amount of cholesterol which reacts with the cholesterol oxidase or cholesterol dehydrogenase comprising

an electrochemical cell having a working electrode, a reference or pseudo reference electrode and optionally a separate counter electrode;

a power supply for applying a potential across the cell; and

a measuring instrument for measuring the resulting electrochemical response;

said method comprising

(i) contacting (1) the reagents (a), (b) and (c), and optionally one or more of (d), (e) and (f), and (2) a high density lipoprotein containing sample, with each other and with the electrodes;

(ii) applying a potential across the electrochemical cell; and

(iii) electrochemically detecting the amount of product formed by measuring the resulting electrochemical response.

20. A method according to claim 19, wherein step (iii) is completed within a period of up to 3 minutes from the time at which the sample is contacted with the reagents (a), (b) and (c).

21. A method of improving the reproducibility of a determination of the amount of cholesterol in high density lipoproteins, comprising reacting a high density lipoprotein containing sample with a surfactant selected from hydroxyethyl glucamide derivatives and N-acyl-N-methyl glucamine derivatives.