Two 4.5 mL light blue top tubes (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. Specimen should be collected prior to factor replacement therapy.
Due to short stability, specimen must either be sent STAT to arrive in the laboratory within 4 hours, or sent STAT. For 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 tube. Label with patient name, I.D. number, collection date, 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 refrigerated, or 7 days frozen.
Two 4.5 mL tubes whole blood or 4 mL plasma.
One 2.7 mL tube whole blood or 2 mL plasma.
Original tubes refrigerated if STAT, or citrated plasma frozen on dry ice.
A normal factor IX level excludes a factor IX inhibitor. If the factor IX level is not decreased on the sample submitted, the assay will be reported as NEGATIVE and only a FIX assay will be billed.
Visible fibrin; moderate to marked hemolysis; specimen received in laboratory beyond stated stability.