Processing Instructions

Fasting (overnight preferred, 4 hours minimum). Infants should be drawn just before next feeding (2-3 hours without total parenteral nutrition, if possible).

Draw in a Green Sodium or Lithium Heparin tube. Centrifuge and separate plasma from cells within 2 hours of collection avoiding buffy coat material. Send 0.5 mL plasma frozen in a screw capped plastic vial. CRITICAL FROZEN.