-Citrated Blue Top Tube (BTT) must be drawn to the fill line.
-Completely invert tube three or four times to mix. Do Not Shake.
-Centrifuge tube at 3000 rpm for 10 minutes or Stat Spin for 3 minutes at 8500 rpm with the brake OFF as soon
as possible after collection.
-Perform testing within 4 hours of sample collection or transfer plasma (avoiding platelet contamination) to polypropylene tube with plastic pipette for storage within two hours of collection.
-If sending to another testing location: Send one frozen aliquot (1 mL) labeled with both APTT and Protime-INR labels if both APTT and Protime-INR ordered.