1 mL serum from a plain red top tube. Allow sample to clot in an upright position for at least 60 minutes, then centrifuge sample and transfer 0.5 mL serum to each of two plastic transport tubes within 2 hours of collection. Clearly label tubes as serum from a plain red top tube. freeze. Critical Frozen (CFZ). When multiple tests are ordered, submit separate tubes for this test.
1 mL EDTA (lavender top) or heparin (green top) plasma. centrifuge sample and separate plasma from cells within 2 hours of collection. Transfer 0.5 mL plasma to each of two plastic transport tubes. Clearly label tubes as EDTA or heparin plasma. Freeze. Critical Frozen (CFZ). When multiple tests are ordered, submit separate tubes for this test.