Method Name
Chromogenic/Inhibition of Factor Xa
Aliases
Unfractionated Heparin Level; Heparin Level; UFH; Anti-Xa (UFH), Heparin Level (Unfractionated)
Specimen Required
One full 2.7 mL blue top tube (3.2% sodium citrate). Specimen will be rejected if the tube is underfilled or overfilled.
Specimen Minimum Volume
2.7 mL of blood
Specimen Stability Information
Specimen is stable for 1 hour at room temperature. Platelet-poor plasma is stable for 4 hours. Stability can be extended to 2 weeks if platelet poor plasma is frozen at -20 degrees C.
Performing Laboratory
As ordered. Turn around time is 4 hours.
Reference Values
Therapeutic Range = 0.3 – 0.7 IU/mL