Collect blood into a plain vacutainer (red top) and allow the blood to clot at RT for 30 minutes, then centrifuge at 1500 x g for 15 min. Transfer the clear serum to a labeled 12 x 75 mm polypropylene tube. Store at -80o C until time of assay.
The R&D Systems enzyme immunoassay (EIA) measures the free steroid only and requires a minimum 4-fold dilution prior to assay.
Suggested blood sample size: 1 ml
