One 4.5 mL light blue top tube (sodium citrate). Collect by careful venipuncture to avoid tissue fluid contamination or hemolysis. Do not use needles smaller than 23 gauge. Fill tube to maximum draw, at least 90% full. Mix by gentle inversion.
Due to short stability, specimen must either be sent STAT to arrive at laboratory within 4 hours, or sent frozen. If STAT, refrigerate and keep capped in original tube. Call for STAT pick-up. For standard delivery, centrifuge to produce platelet poor plasma (at least 1700 X G for 15 minutes) and using a plastic pipette, transfer the top 2/3 of the plasma into a plastic vial. Label with patient name, I.D. number, test, and “citrated plasma.” Freeze immediately. Send to the laboratory within 7 days. If multiple tests are ordered, freeze a separate aliquot for this test.
4 hours refrigrated, or 7 days frozen.
4.5 mL light blue top tube (sodium citrate) or 2 mL plasma.
1.8 mL light blue top tube (sodium citrate) or 0.5 mL plasma.
Original tubes refrigerated if STAT, or plasma frozen on dry ice in a Styrofoam container.
Patients must not be receiving unfractionated heparin. Heparin will interefere with clot-based factor assays.
Visible fibrin; moderate to marked hemolysis; specimen received in laboratory beyond the stated stability.