Factor 2 activity

Alphabetical Test listing

Factor 2 activity-13366

Factor 2 activity
Factor II activity

Evaluate an isolated prolonged PT or when there is prolongation of both the APTT and PT and to document specific factor II deficiency.

  • Ideally the patient should not be on anticoagulant therapy.
  • Avoid warfarin (Coumadin®) therapy for two weeks prior to the test and heparin, direct Xa, and thrombin inhibitor therapies for about three days prior to testing.
Sodium citrate (Na cit) plasma
1.0 mL
  • Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate
  • Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio
  • The sample should be mixed immediately by gentle inversion, at least six times, to ensure adequate mixing of the anticoagulant with the blood
  • A discard tube is not required prior to collection of coagulation samples unless the sample is collected using a winged (butterfly) collection system
    • With a winged blood collection set a discard tube should be drawn first to account for the dead space of the tubing and prevent under-filling of the evacuated tube
  • When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes
    • Any tube containing an alternative anticoagulant should be collected after the blue-top tube
    • Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes
  • If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted
  1. Spin within two (2) hours of sample collection
  2. Transfer plasma to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as Na cit plasma
  3. Freeze



Frozen - 28 days

Freeze/thaw cycles - stable x3

  • Severe hemolysis
  • Improper labeling
  • Clotted specimen
  • Specimen diluted with I.V. fluids
  • Samples thawed in transit
  • Improper sample type
  • Sample out of stability


LabCorp Burlington (086231): R-LC
2 - 3 days

Factor II activity is determined utilizing a Prothrombin Time (PT)-based one-stage clotting time assay. Factor II- depleted plasma is used as the substrate and the clotting time with the patient plasma is compared to the clotting time of normal pooled plasma.


50 - 154%

Result 3289-6