4 mL EDTA plasma. Critical Frozen (CFZ).
1. Collect sample mid-morning after patient has been active for at least 2 hours.
2. Centrifuge EDTA (lavender top) tubes immediately after collection. Transfer 2 mL plasma to two plastic transport tubes. Clearly label tubes as EDTA plasma. freeze. Critical Frozen (CFZ).
3. Rubber-band both samples together for transport to the laboratory. When multiple tests are ordered, submit separate tubes for this test.