Web: | mayocliniclabs.com |
---|---|
Email: | mcl@mayo.edu |
Telephone: | 800-533-1710 |
International: | +1 855-379-3115 |
Values are valid only on day of printing. |
Deuterated stable isotopes (d4-cortisol, d7-androstenedione, d8-17-hydroxyprogesterone) are added to a 0.1-mL serum sample as internal standards. Cortisol, androstenedione, 17-hydroxyprogesterone, and the internal standards are extracted from specimens using a Strata X 30-mg cartridge and eluted from the cartridge with methanol. The extracts are then dried down under nitrogen, reconstituted with 75 mcL of 70/30 methanol/H2O containing 1 g/mL of estriol and analyzed by liquid chromatography-tandem mass spectrometry using multiple-reaction monitoring. A calibration curve is generated by spiking standards into a bovine serum albumin buffer and extracted with each batch of new working internal standard. Controls are extracted with each batch.(Unpublished Mayo method)
Monday through Friday; 4 p.m.