Specimen Requirements

Plasma

Container/Tube: Blue top tube (buffered sodium citrate)

Specimen Volume: Full Tube to appropriate line

Collection:

1. PTT specimens from non heparinized patients can be centrifuged (centrifuge specimens for 10 min at 3500 rpm) or un-centrifuged with plasma remaining on top of cells in an unopened tube, kept at ROOM TEMPERATURE (18-24 Celsius) for no longer than 4 hours.
2. PTT specimens from patients on unfractionated heparin therapy should be centrifuged and the plasma removed from the cells within 1 hour of collection and kept at Room Temperature or 2-8 Celsius and tested within 4 hours of collection.
3. If testing cannot be performed within these times, platelet-poor plasma should be removed form the cells and frozen at -20 Celsius for up to 2 weeks or at -70 Celsius for up to 12 months.
4. Properly label tube with patients name, DOB, requisition number and if plasma has been separated; type of tube sample drawn from, i.e. BLUE.