Plasma, Platelet-poor

Withdraw 45 mL of human blood into a 50 mL plastic syringe containing 5 mL of a sterile 3.8% w/v solution of sodium citrate. Immediately centrifuge the citrated whole blood at 1150 g for 30 minutes at 4°. Remove the upper two thirds of the supernatant plasma using a plastic syringe and immediately centrifuge at 3500 g for 30 minutes at 4°. Remove the upper two thirds of the liquid and freeze it rapidly in suitable quantities in plastic tubes at a temperature of –40° or below. Use plastic or siliconised equipment throughout.