Centralized Core Laboratory:Hematology
Blue top (sodium citrate) tube
2.7 mL (minimum 1.8 mL)
Cause for rejection:
Specimens which have visible hemolysis, are clotted, collected in wrong tube, diluted with IV fluids, contaminated with heparin, tubes that are over or under filled, specimens not kept on ice, or specimens received more than one hour post collection.
Specimens should be spun down & platelet poor plasma frozen if coming from an off site facility (plasma volume minimum 0.5 mL)
If collected at an offsite location, send by a STAT Courier to Hospital lab.
Reference range: 50-150%
von Willebrand Factor Activity