Corticosteroid-Binding Globulin (CBG)
Also known as: CB GLOB
Use
The Corticosteroid-Binding Globulin (CBG) test measures the level of corticosteroid-binding globulin in the blood. CBG is a protein that binds cortisol and other corticosteroids, regulating their bioavailability and transport in the bloodstream. This test can help in evaluating conditions related to abnormal cortisol levels, such as Cushing's syndrome, Addison's disease, and congenital adrenal hyperplasia. It is also useful in evaluating liver function and can provide context around cortisol assay results.
Special Instructions
This test is performed by a non-ARUP laboratory and is not cleared or approved by the FDA. It requires a separate specimen if multiple tests are ordered, as it is not performed at ARUP Laboratories. New York state approval has been obtained for this test.
Limitations
The performance characteristics of this test were determined by Labcorp and have not been reviewed or cleared by the FDA. Variability in test results may occur due to differences in methodologies used by different laboratories, and the test's accuracy can be influenced by the presence of proteins or interfering substances in the serum. Timely processing and proper freezing of the specimen are crucial for accurate results.
New York Approved
Methodology
Immunoassay (RIA)
Biomarkers
LOINC Codes
- 3033-8
Result Turnaround Time
6-13 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP standard transport tube
Collection Instructions
Collect blood in a plain red or serum separator tube (SST). Separate from cells within one hour of collection. Transfer serum to an ARUP standard transport tube and freeze immediately.
Storage Instructions
Critical frozen.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 48 hours |
| Frozen | 10 months |