One 7.5 mL serum separator tube (SST). Also acceptable: One 4.5 mL green top plasma separator tube (PST), or one 4 mL grey top tube (potassium oxalate/sodium fluoride) for a post-prandial (after meal).
Allow to clot, centrifuge and immediately separate serum or plasma into a plastic vial. Centrifuge SST within one hour of collection. Specimen drawn in SST or PST can be transported in the original tube after centrifugation. Refrigerate.
24 hours ambient, 7 days refrigerated, or indefinitely frozen.