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Laboratory Medicine

Test Catalogue

Dexamethasone Suppression Tests

Test Name

Dexamethasone Suppression Tests

Gold Tube Specimen Type / Requirements

Container Type = Gold (SST)

Minimum Volume = 1mL Serum

Tube must fill to at least ½ or greater of its vacuum capacity

Specimen Handling

Collection Instructions: Collect sample in a gold top tube (SST). Serum cortisol is ordered when a patient is given dexamethasone. The test is looking for the patient's cortisol level in response to dexamethasone.

Laboratory Staff Instructions: Let sample clot adequately at room temperature before centrifugation. Separate serum or plasma from cells within 2 hours of collection.

Stability: Cortisol is stable at room temperature for 1 week, refrigerated for 1 week and frozen at -15 to -20°C for 3 months.

Transportation: Transport at room temperature ASAP. Place on ice if time of collection to time sample get to lab exceeds 2hrs

Sample Rejection Criteria: Avoid Hemolysis, unlabeled and/or samples of non suffecient quantity.

Required Documentation

Turnaround Time (TAT)

1 hour for Trauma or Stat
2 hours for routine

Test Utilization

Reference Value


AM: 193-690 nmol/L

PM: 83-303 nmol/L



AM: 190-740 nmol/L

PM: 30-300 nmol/L

Test Code



Competitive Immunoassay, Direct Chemiluminescence

Testing Location


Other Information

Last Updated: June 05, 2020