Home
HelpTest Code LAB2690 21-Hydroxylase Antibodies, Serum
Additional Codes
Adrenal Ab
Ordering Guidance
Testing for autoantibodies against 21-hydroxylase is recommended following confirmation of adrenal insufficiency to help differentiate between causes of primary adrenal insufficiency
Shipping Instructions
Ship specimen frozen on dry ice
Specimen Required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial to remove from cells or gel prior to shipping.
Useful For
Investigating adrenal insufficiency
Aiding in the detection of those at risk of developing autoimmune adrenal failure in the future
Method Name
Enzyme-Linked Immunosorbent Assay (ELISA)
Reporting Name
21-Hydroxylase Ab, SSCH Clinical System Name: 21-Hydroxylase Antibodies
Specimen Type
SerumSpecimen Minimum Volume
0.2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen | 14 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Reference Values
Negative
Method Description
A reference preparation, controls, and patient specimens are incubated with a reaction enhancer overnight in a coated enzyme-linked immunosorbent assay (ELISA) plate. 21-Hydroxylase (21-OH) antibodies (Ab) act divalently and form a bridge between 21-OH Ab coated on ELISA plate wells and liquid phase 21-OH biotin. The resulting antigen-antibody-antigen complexes are then detected by the addition of streptavidin peroxidase and tetramethylbenzidine to produce a colorogenic reaction. Stop solution is added to halt the reaction, and absorbance is read using an ELISA plate reader. The absorbance of each well is directly proportional to the amount of antibody present. Positive and negative determinations are based on index values. Index values are calculated from the mean value of duplicate sample wells and compared to a reference value.(Package insert: 21-Hydroxylase Autoantibody [21-OHAb] ELISA Kit, Kronus; 04/2024)
Day(s) Performed
Wednesday
Report Available
3 to 9 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
83516
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| 21OH | 21-Hydroxylase Ab, S | 85363-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 607788 | 21-Hydroxylase Ab, S | 85363-0 |