PROTEIN S ACTIVITY
1-Blue top tube (sodium citrate 3.2%). Tube must be full when collected. Centrifuge specimen and remove plasma to a transport tube and freeze. Indicate on tube “plasma/blue top”. Contact lab for dry ice for shipment.
Frozen 3 weeks
Diagnosis of congenital protein S deficiency which may increase the risk of thrombosis. An abnormal result should be followed up with protein S antigen, total and free.