Specimen Requirements

Collect 1.0 ml citrated plasma (blue top tube). Allow tube to fill to vacuum in order to maintain proper ratio of blood to anticoagulant (9:1) [4.5 ml blood: 0.5 ml anticoagulant]. Centrifuge and transfer plasma to plastic tube.

If the patient is on periodic doses of heparin, samples should NOT be drawn within 2 hours post dose.