Cortisol Assay, 4 Samples: PRE (Baseline) and 3 POST Dexamethasone Suppression
Specimen
PRE: 0.5 mL serum in red top, white top, or serum separator tube for baseline sample (labeled PRE); each POST: 0.5 mL serum in red top, white top, or serum separator tube for each post sample (labeled POST)
Test Description
This test measures cortisol concentrations before and after administration of exogenous dexamethasone. This suppression test includes four samples; baseline cortisol prior to dexamethasone administration and three additional cortisol samples post dexamethasone administration (last occurring at 8 hours). Samples taken at 2 or 6 hours are interpreted similarly to those obtained at 4 hours.