Specimen Requirements

Container/Tube: Light blue-top (sodium citrate) tube

Specimen: 2.7 mL of sodium citrate blood

Transport Temperature: Ambient. Stable at room temperature for 4 hours.

Specimen testing must be complete within 4 hours of collection so transport uncentrifuged tube to the lab as soon as possible.

Collection Instructions: Tube must be full. Do not centrifuge. If collected through an indwelling catheter, line should be flushed with saline and first 10 mL of blood should be discarded. Using a transfer device, immediately transfer 2.7 mL of blood to tube, and mix gently 3 or 4 times. If collected through a blood collection set (butterfly), a discard tube must first be drawn to eliminate dead space from tubing. Gently invert 3 to 4 times to mix blood. Do not uncap tube.

Note: For monitoring heparin therapy, the test should not be drawn less than 3 hours following administration of heparin.  Samples for unfractionated heparin testing should be received in the lab within 1 hour of collection.