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. Duly filled Coagulation Requisition Form AND Test Send Out Consent Form is mandatory.