Fill up a Light Blue Top tube as completely as possible and mix by gently inverting the tube 5-6 times.
Inadequate filling will distort the exact ratio of 1 part sodium citrate to 9 parts blood required for accurate results.
Immediately centrifuge the specimen at 1500 RCF for 15 minutes.
Pipette the supernatant plasma and transfer to a plastic transport tube.
Re-centrifuge plasma in the transport tube at 1500 RCF for 15 minutes to make sure that no red blood cells are present.
Pipette the top two-thirds of the supernatant plasma and transfer 2.0 mL to a second transport tube, labeled with two patient identifiers.
Label aliquot tube as citrate plasma and immediately freeze at -20 °C or lower for transport.