Serum (preferred) or plasma, frozen
Red-top tube, gel-barrier tube, lavender-top (EDTA) tube, or green-top (heparin) tube
Separate serum or plasma from cells within one hour of collection. Transfer to a plastic transport tube and freeze. To avoid delays in turnaround time when requesting multiple test on frozen samples, please submit separate frozen specimens for each test requested.
Freeze; stable for one year. Stable at room temperature for six days or refrigerated for 14 days.