Reference solution

• US 20050130285A1
• Filed: 11/29/2004
• Published: 06/16/2005
• Est. Priority Date: 11/28/2003
• Status: Abandoned Application

• Current Assignee: Radiometer Medical ApS (Danaher Corporation)
• Original Assignee: Radiometer Medical ApS (Danaher Corporation)
• Inventors: Lunding, Gitte
• Application Number:
  US10/998,009
• Publication Number:
  US 20050130285A1
• Time in Patent Office: Days
• US Class Current: 435/195
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/34 involving hydrolase
• CPC Class Codes: G01N 2333/986 acting on amide bonds in cyclic amides (3.5.2), e.g. beta-lactamase (penicillinase, 3.5.2.6), creatinine amidohydrolase (creatininase, EC 3.5.2.10), N-methylhydantoinase (3.5.2.6)
• CPC Class Codes: G01N 33/70 involving creatine or creatinine
• CPC Class Codes: G01N 33/96 involving blood or serum control standard
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing

Abstract

A reference solution is provided, which comprises, in a liquid phase, at least one of a first compound and a second compound which are mutually convertible into each other, and at least one catalyst, which catalyzes the conversion between the first compound and the second compound.

Claims

1. A reference solution comprising, in a liquid phase:

at least one of a first compound and a second compound which are mutually convertible into each other; and

at least one catalyst, which catalyzes the conversion between said first compound and said second compound.

2. The reference solution according to claim 1 wherein the at least one catalyst is an enzyme.

3. The reference solution according to claim 2 wherein the enzyme is a hydrolase.

4. The reference solution according to claim 1 wherein the first compound is an amide or an ester.

5. The reference solution according to claim 1 wherein the first compound is creatinine and the second compound is creatine.

6. The reference solution according to claim 5 wherein the at least one catalyst is creatinine amidohydrolase.

7. The reference solution according to claim 2 wherein the first compound is carbon dioxide and the enzyme is carbonic anhydrase.

8. A kit comprising:

a container holding the reference solution according to claim 1, comprising at least a first compartment and a second separate compartment;

a liquid first phase contained in the first compartment; and

a second phase contained in the second separate compartment, said second phase comprising the at least one of a first compound and a second compound and the at least one catalyst.

9. The kit according to claim 8 wherein the container further comprises a third separate compartment, and wherein the at least one of a first compound and a second compound is contained in the second separate compartment and the at least one catalyst is contained in the third separate compartment.

10. A method of operating the kit according to claim 8 wherein the second phase is transferred to the first phase by providing fluid communication between the compartments.

11. A container holding the reference solution according to claim 1.

12. A method of preparing the reference solution according to claim 1, comprising the steps of:

adding to a liquid phase;

the at least one of a first compound and a second compound; and

the at least one catalyst; and

determining, before or after addition of the at least one catalyst, the equilibrium concentrations of the first compound and the second compound for a selected temperature.

13. The method according to claim 12 wherein the step of determining the equilibrium concentrations comprises:

measuring the total concentration of the first and second compounds; and

computing the equilibrium concentrations therefrom.

14. The method according to claim 12 wherein the step of determining the equilibrium concentrations comprises:

measuring the concentrations of each of the first and second compounds; and

computing the equilibrium concentrations therefrom.

15. The method according to claim 12 wherein the step of determining the equilibrium concentrations comprises:

allowing establishment of the equilibrium concentration of the first and second compounds after addition of the at least one catalyst;

measuring the equilibrium concentration of one of the first and second compounds; and

computing the equilibrium concentration of the other of the first or second compound therefrom.

16. The method according to claim 12 wherein the step of determining the equilibrium concentrations comprises:

adding to the liquid phase the at least one of the first compound and the second compound in a predetermined amount; and

optionally computing the equilibrium concentrations therefrom.

17. A method comprising using the reference solution according to claim 1 for calibration or quality control of a sensor, which is sensitive to at least one of the first and the second compound or a parameter derived therefrom.

18. The method according to claim 17 wherein the reference solution, prior to calibration or quality control of the sensor, is conditioned at a conditioning temperature in the temperature range of 18-32°

C.

19. The method according to claim 18 wherein the temperature range is 20-25°

C.

20. The method according to claim 17 wherein the reference solution, prior to calibration or quality control of the sensor, is conditioned for a period in the conditioning period range of 0.1-8 hours.

21. The method according to claim 20 wherein the conditioning period range is 0.1-3 hours.