Vitamin D assay

• US 7,087,395 B1
• Filed: 01/16/2001
• Issued: 08/08/2006
• Est. Priority Date: 01/16/2001
• Status: Expired due to Term

• Current Assignee: Quest Diagnostics Investments Incorporated (Quest Diagnostics Incorporated)
• Original Assignee: Quest Diagnostics Investments Incorporated (Quest Diagnostics Incorporated)
• Inventors: Tran, Jacqueline, Garrity, Martha
• Primary Examiner(s): Le, Long V.
• Assistant Examiner(s): Cook, Lisa V.
• Application Number:
  US09/761,969
• Time in Patent Office: 2,030 Days
• Field of Search: 436/501, 436/536, 436/542, 436/518, 424/1.49, 435/6, 435 71- 79, 435/91.2, 435/7.92, 435/7.93, 536/23.1, 536/24.3, 536/24.33, 422/6, 422/1
• US Class Current: 435/7.93
• CPC Class Codes: G01N 33/82 involving vitamins or their receptors

Abstract

The present invention features a kit and a method of using the kit for determining a concentration of a vitamin D component. The kit comprises a releasing composition and a detecting composition. The releasing composition comprises an aqueous base component. In one embodiment, the releasing composition is substantially free from an organic solvent.

Claims

1. A kit for determining a concentration of 25-hydroxy vitamin D (25-OH-D) in a sample, comprising:

a releasing composition including from about 0.01 to about 5% of a cyclodextrin, from about 0.01 to about 5% of a sodium salicylate, and from about 0.1 to about 1.0 M NaOH, the cyclodextrin, the salicylate, and the NaOH being provided in an amount effective to reduce interference from a protein or a lipid with 25-hydroxy vitamin D present in a sample;

25-hydroxy vitamin D coupled to a solid phase;

vitamin D binding protein; and

a vitamin D binding protein antibody coupled to a label present in an amount that produces a detectable signal when 25-hydroxy vitamin D is present in the sample.

2. A kit of claim 1, wherein the cyclodextrin, the salicylate, and the NaOH are provided in an amount effective to reduce interference from proteins or lipids with 25-hydroxy vitamin D present in a sample of a mammal fluid.

3. A kit of claim 2 wherein the mammal fluid is selected from the group consisting of milk whole blood, serum, and plasma.

4. A kit of claim 2 wherein the mammal fluid comprises a human serum.

5. A kit of claim 1 wherein the releasing composition comprises about 0.35 to about 0.5 M of NaOH.

6. A kit of claim 1 wherein the releasing composition is free of an organic solvent.

7. A kit of claim 1 wherein the cyclodextrin is selected from the group consisting of alpha-cyclodextrin and a beta-methylated cyclodextrin.

8. A kit of claim 1 wherein the releasing composition comprises about 2% of an alpha-cyclodextrin.

9. A kit of claim 1 wherein the releasing composition comprises about 0.05% of a beta-methylated cyclodextrin.

10. A kit of claim 1 wherein the releasing composition comprises about 0.5 to about 5% of the sodium salicylate.

11. A kit of claim 1 wherein the releasing composition further comprises about 0.01 to about 0.1% of a surfactant.

12. A kit of claim 1 wherein the releasing composition forms a homogeneous mixture with a mammal fluid.

13. A kit of claim 1 wherein the label is selected from the group consisting of a chemiluminescent label, a fluorescent label and a radio-active label.

14. A kit of claim 1 wherein the vitamin D binding protein antibody is an acridinium-labeled antibody.

15. A kit of claim 1 wherein the solid phase is a magnetic particle.

16. A kit of claim 1 wherein the 25-hydroxy vitamin D coupled to a solid phase is in the form of 25-hydroxy vitamin D coated magnetic particles, the vitamin D binding protein antibody is coupled to an acridinium label, and the 25-hydroxy vitamin D coated magnetic particles, the acridinium labeled vitamin D binding protein antibody, and the vitamin D binding protein are present in a single composition.

17. A kit of claim 1, wherein the releasing composition further includes from about 0.01% to about 0.1% of a surfactant, and the antibody is labeled with acridinium.