Test system for determining an analyte in a liquid sample

• US 20050142032A1
• Filed: 10/29/2004
• Published: 06/30/2005
• Est. Priority Date: 10/31/2003
• Status: Abandoned Application

• Current Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Nortmeyer, Christine, Hoenes, Joachim, Horn, Carina
• Application Number:
  US10/977,379
• Publication Number:
  US 20050142032A1
• Time in Patent Office: Days
• US Class Current: 422/58
• CPC Class Codes: G01N 33/526 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/723 Glycosylated haemoglobin
• CPC Class Codes: G01N 33/86 involving blood coagulating time or factors, or their receptors

Abstract

A test system for determining an analyte in a liquid sample is provided comprising at least two compartments, wherein the detection reactions necessary to determine the analyte are carried out in a first compartment and an analytical determination of at least one substance which participates in the detection reactions and is different from the analyte, the indicator substance, takes place in a second compartment. The two compartments are separated from one another in a manner which allows the indicator substance to pass into the second compartment and at least partially prevents passage of other substances that could interfere with the analytical determination of the indicator substance in the second compartment. At least one other substance is present in an immobilized form in the second compartment which, as a capture substance, selectively enriches the indicator substance in the second compartment. The indicator substance is not a coenzyme and at the same time the capture substance is not a catalytically inactive coenzyme-binding protein.

Claims

1. A test system for determining an analyte in a liquid sample comprising at least two compartments, the detection reactions necessary to determine the analyte being carried out in a first compartment and an analytical determination of at least one indicator substance being carried out in a second compartment, wherein

a) the two compartments are separated from one another in a manner which allows the indicator substance to pass into the second compartment and which at least partially prevents passage of other substances which can interfere with the analytical determination of the indicator substance in the second compartment;

b) at least one other substance is present in an immobilized form in the second compartment which, as a capture substance, selectively enriches the indicator substance in the second compartment; and

c) the indicator substance is not a coenzyme and at the same time the capture substance is not a catalytically inactive coenzyme-binding protein.

2. The test system of claim 1, wherein the indicator substance participates in the detection reaction and is different from the analyte.

3. The test system of claim 1, wherein the liquid sample comprises a biological sample.

4. The test system of claim 3, wherein the biological sample comprises whole blood or a blood product derived therefrom.

5. The test system of claim 4, wherein the blood product comprises serum or plasma.

6. The test system of claim 1, wherein a chemical or enzymatic detection reaction for determining the analyte takes place in the first compartment in which the indicator substance is formed or converted in a manner which correlates with the presence of the analyte in the liquid sample.

7. The test system of claim 6, wherein the indicator substance is formed or converted in a manner which correlates with the concentration of the analyte in the liquid sample.

8. The test system of claim 7, wherein the indicator substance is formed or converted in a manner which correlates with the concentration of the analyte in the liquid sample on the basis of stoichiometric relationships.

9. The test system of claim 1, wherein the indicator substance has a molecular weight of less than about 15,000 g/mol.

10. The test system of claim 1, wherein the indicator substance has a molecular weight of less than about 2,000 g/mol.

11. The test system of claim 1, wherein the indicator substance has a molecular weight of less than about 1,500 g/mol.

12. The test system of claim 1, wherein the indicator substance establishes an equilibrium distribution between the first and second compartment.

13. The test system of claim 12, wherein the equilibrium distribution between the first and second compartment is established by diffusion.

14. The test system of claim 1, wherein the two compartments are separated by designing the second compartment in the form of a selectively permeable matrix.

15. The test system of claim 14, wherein the selectively permeable matrix is selected from a gel, film, membrane, or polymer layer.

16. The test system of claim 1, wherein the selective enrichment of the indicator substance in the second compartment is based on specific interactions between the indicator substance and the capture substance.

17. The test system of claim 16, wherein the selective enrichment of the indicator substance in the second compartment is further based on a) hydrophilic/hydrophobic interaction;

b) ionic interaction;

c) complex formation;

d) a chemical precipitation reaction;

e) specific binding between the partners of a specific binding pair;

or f) combinations thereof.

18. The test system of claim 17, wherein the complex formation comprises chelate formation.

19. The test system of claim 17, wherein the specific binding between the partners of a specific binding pair are between the partners of a binding pair according to the lock and key principle selected from antibodies/antigens, proteins/cofactors, complementary nucleic acids, biological binding pairs, or combinations thereof.

20. The test system of claim 19, wherein the biological binding pairs are biotin/avidin or biotin/streptavidin.

21. The test system of claim 1, wherein the capture substance in the second compartment is selected from a carbohydrate, a polyelectrolyte, a complexing agent, an anion, a cation, a binding partner of a specific binding pair, or combinations thereof.

22. The test system of claim 2.1, wherein the carbohydrate is selected from cyclodextrin, polyethylene glycol, albumin, or combinations thereof.

23. The test system of claim 21, wherein the polyelectrolyte is selected from polysulfonic acid, a polycation, or combinations thereof.

24. The test system of claim 21, wherein the complexing agent comprises an ethylenediamine tetraaceitc acid derivative.

25. The test system of claim 21, wherein the binding partner of a specific binding pair is selected from antibodies/antigens, proteins/cofactors, complementary nucleic acids, biological binding pairs, or combinations thereof.

26. The test system of claim 25, wherein the biological binding pairs are biotin/avidin or biotin/streptavidin.

27. The test system of claim 1, wherein the capture substance is immobilized by enclosure in a matrix.

28. The test system of claim 27, wherein the matrix which immobilizes the capture substance at the same time separates the two compartments.

29. The test system of claim 1, wherein the indicator substance is determined in the second compartment by optical or electrochemical methods.

30. The test system of claim 29, wherein the optical method comprises fluorimetric or photometric methods.

31. The test system of claim 29, wherein the electrochemical method comprises amperometric or potentiometric methods.

32. A method for determining coagulation parameters in whole blood or a blood product derived therefrom comprising:

a) converting a fluorescently labelled thrombin substrate during the course of detection reactions in a first compartment of a test apparatus to form a fluorescent indicator substance;

b) enriching the indicator substance by specific capture substances in a second compartment of the test apparatus while excluding interfering sample components; and

c) detecting the indicator substance in the second compartment using optical methods.

33. The method of claim 32 further comprising determining thrombin content and parameters derived therefrom selected from prothrombin time, activated clotting time, and activated partial thromboplastin time.

34. The method of claim 32, wherein the fluorescently labelled thrombin substrate is Pefafluor TH.

35. The method of claim 32, wherein the fluorescent indicator substance is aminomethylcoumarin.

36. The method of claim 32, wherein the specific capture substrate is selected from hydroxypropyl-beta-cyclodextrin or polyethylene glycol 20000.

37. The method of claim 32, wherein the second compartment is in the form of an open film matrix.

38. The method of claim 32, wherein the interfering sample components are blood cells and chromophoric substances.

39. The method of claim 38, wherein the chomophoric substance is haemoglobin.

40. The method of claim 32, wherein the optical method is a fluorescent-optical method.

41. A method for determining glycosylated haemoglobin in whole blood or a blood product derived therefrom comprising:

a) providing an indicator substance in a first compartment of a test apparatus, the indicator substance comprising a low molecular weight labelled reagent which specifically binds to glycosylated haemoglobin during the course of a detection reaction;

b) enriching the indicator substance that is not bound to glycosylated haemoglobin with specific enriching in a second compartment of the test apparatus, while excluding interfering sample components and excluding the indicator substance bound to glycosylated haemoglobin; and

c) detecting the indicator substance in the second compartment using optical methods.

42. The method of claim 41, wherein the low molecular weight labelled reagent is a low molecular weight fluorescently labelled boronic acid.

43. The method of claim 41, wherein the specific capture substances are selected from carbohydrates and diols.

44. The method of claim 41, wherein the interfering sample components are blood cells and chromophoric substances.

45. The method of claim 44, wherein the chromophoric substance is haemoglobin.

46. The method of claim 41, wherein the optical method is a fluorescent optical method.