Specimen

3 mL Whole blood in 1 Blue Top (Sodium Citrate) tube. Mix thoroughly by inversion. Transport to Lab within 4 hours. If this is not possible, make PPP within 1 hour of collection as follows: Centrifuge sample at 3600 rpm for 15 min. & transfer supernatant to a clean plastic tube. Centrifuge this supernatant again at 3600 rpm for 15 min. & finally transfer the supernatant (PPP) to 1 labelled, clean plastic screw capped vial. FREEZE IMMEDIATELY. Ship frozen. DO NOT THAW. Overnight fasting is preferred. Duly filled Coagulation Requisition Form (Form 15) is mandatory. It is recommended that patient discontinues Heparin for 1 day and Oral Anticoagulants for 7 days prior to sampling as these drugs may affect test results. Discontinuation should be with prior consent from the treating Physician.

Usage

Protein S is a vitamin K dependent plasma glycoprotein produced in the liver. It acts as a necessary cofactor to activated Protein C in the proteolytic inactivation of procoagulant factors Va and VIIIa. Congenital Protein S deficiency is an autosomal dominant disorder seen in 1% to 3% of patients with venous thromboembolism. Heterozygous Protein S deficiency carriers have approximately 10 fold increased risk of venous thromboembolism. They are also predisposed to recurrent abortions, preeclampsia, intra uterine growth retardation & still births.