Tube must be filled completely and kept tightly stoppered at all times. Mix well. Specimen must be placed on ice immediately. Separate plasma from cells within 15 minutes of collection. Patient should NOT clench fist. Transfer specimen to plastic transport tube before freezing. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. Avoid contamination of samples by ammonia from smoking or traffic in the laboratory or patient's room, glassware, or water. 1mL Frozen Plasma from Lavender-top (EDTA) tube; EDTA is the only acceptable anticoagulant.