Draw blood in chilled, siliconized glass or plastic tube. Immerse in an ice bath immediately after collection. Centrifuge sample and separate plasma from cells immediately. Transfer plasma to a plastic transport tube. Clearly label tube as EDTA plasma. Freeze. Critical Frozen (CFZ).
Note: Do not collect samples from patients receiving therapy with high biotin doses (>5 mg/day) until at least 8 hours following the last biotin administration. When multiple tests are ordered, submit a separate tube for this test.