Preferred Specimen(s) 3.2% sodium citrate (light blue-top) tube
Instructions Correct ratio of blood to citrate is critical (9:1). Do not overfill or underfill collection tube. Mix by inversion 4 times. For non-heparinized patients, maintain specimen at room temperature. Do not uncap. Stable 24 hours at room temperature. For heparinized patients or if testing will be delayed longer than 24 hours, centrifuge specimen within 1 hour of collection at 1500 RCF (relative centrifugal force) for 15 minutes. Transfer plasma to a plastic screw-cap vial and freeze at -20° C immediately.
Transport Container
Whole blood: 3.2% sodium citrate (light blue-top) tube
Plasma: Plastic screw-cap vial (frozen)
Transport Temperature
• Room temperature: (Light blue-top) tube – whole blood (if specimen sent to laboratory within 4 hours of collection)
• Frozen: Plasma
Reject Criteria
• Gross hemolysis
• Improper blood to citrate ratio
• Clotted
• Age of specimen
• High hematocrits
Methodology Clotting method