One 7.5 mL serum separator tube (SST). Also acceptable: One 5 mL red top tube. Draw specimen between 0600 and 1000 if possible, as testosterone levels vary throughout the day.
Handling:
Allow to clot, centrifuge and separate serum from cells within 2 hours. Refrigerate. Freeze at -20° if specimen cannot be assayed within 7 days. Allow no more than one freeze/thaw cycle. If multiple tests are ordered, send a separate specimen for this test.
Stability:
7 days refrigerated at 2-8° C, or 2 months frozen at -20° C.
Standard Volume:
1 mL serum.
Minimum Volume:
0.5 mL serum.
Transport:
Refrigerated, or frozen on dry ice.
Comments:
For testing on patients less than 1 year of age, see Testosterone, Women and Children (87145).