ACTH, Plasma (211)
Use
Determination of ACTH (adrenocorticotropic hormone) is clinically useful in the differential diagnosis of pituitary or adrenal disorders such as Cushing syndrome, Addison disease, ectopic ACTH syndrome, hypopituitarism, and ACTH‑producing tumors. It helps distinguish between primary and secondary forms of adrenal dysfunction and evaluate pituitary–adrenal axis function.
Special Instructions
Specimen should be collected between 7 a.m. and 10 a.m., as results outside this time frame may not correlate with reference ranges. Draw into a lavender-top EDTA tube, pre-chilled or on ice, centrifuge promptly, separate plasma, and freeze immediately. Transport frozen. These handling steps are critical to prevent degradation and ensure result accuracy.
Limitations
ACTH is a labile peptide hormone subject to rapid degradation; delays in processing, inadequate cooling, or transport at ambient or refrigerated temperatures may lead to falsely low results. Pulsatile secretion means single measurements may not capture peak levels. Interference can occur in immunoassay formats, particularly due to biotin, monoclonal mouse antibodies, or anti‑streptavidin/ruthenium antibodies.
Methodology
Immunoassay
Biomarkers
LOINC Codes
- 2141-0
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1‑3 mL blood yields 0.5‑1.5 mL plasma
Minimum Volume
0.5 mL plasma
Container
Lavender (EDTA) tube, pre-chilled or on ice
Collection Instructions
Draw between 7 a.m. and 10 a.m.; collect in EDTA tube chilled or on ice; centrifuge promptly; separate plasma; freeze immediately.
Storage Instructions
Freeze immediately; transport frozen.
Causes for Rejection
Thawed specimen; serum or heparinized plasma; specimen collected in nonsiliconized glass; specimen not frozen or transported improperly.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unstable |
| Refrigerated | Unstable |
| Frozen | 28 Days |