Phenylalanine, Quantitative, Plasma
Preferred: Frozen plasma from green-top (sodium heparin) tube. Acceptable: Frozen plasma from green-top (lithium heparin) tube, frozen plasma from lavender-top (EDTA) tube or frozen plasma from PPT™. Frozen serum from serum separator tube (SST) or frozen serum from red-top tube will not be rejected. Note: Plasma reference ranges will be applied to all specimen types.
Separate plasma from cells. 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.
Centrifuge, remove plasma from cells, and freeze immediately
Gross hemolysis; room temperature or thawed specimens; specimens collected in yellow-top (ACD) tubes.