One 7.5 mL serum separator tube (SST). Also acceptable: One 4 mL green top tube (heparin), one 4.5 mL plasma separator tube (PST), or one 4 mL lavender top tube (EDTA).
Handling:
Allow to clot, centrifuge SST or PST within 2 hours of collection and transport in original tube. Centrifuge heparin or EDTA within 2 hours of collection, separate the plasma from cells into a plastic vial. Refrigerate.