Lab Test

Factor II Activity

Factor 2, Factor 2 Assay, Factor II Assay , Antrim #26120, EPIC: LAB5179, SOFT: FII


Specimens with hematocrit values greater than 55% must have anticoagulant adjusted. Specimens must be re-collected using a specified whole blood to sodium citrate ratio. Contact the performing Laboratory for specific instructions.

Specimen Collection Criteria

Collect: One Light Blue-top Becton-Dickinson 3.2% Sodium Citrate tube.


Physician Office/Drawsite Specimen Preparation

For optimal results, maintain whole blood specimen at room temperature (20-26°C or 68-78.8°F) prior to transport. Transport whole blood to the Laboratory within 4 hours of collection. If transport within 4 hours is not possible, the following procedure must be followed for accurate results:

  1. Centrifuge the capped tube at 1500 x g for 15 minutes.
  2. Transfer plasma with a plastic pipette into a plastic polypropylene centrifuge tube, cap and centrifuge an additional 15 minutes at 1500 x g to obtain platelet poor plasma (PPP) which has a platelet count less than 10 bil/L. Plasma with a platelet count of less than 10 bil/L is critical for accurate results.
  3. Immediately remove only the top two-thirds of the PPP and transfer it into a plastic tube.
  4. Freeze (-20°C/-4°F or below) the PPP immediately.
  5. Transport frozen on DRY ICE. Specimen must remain frozen during transport.  

Preparation for Courier Transport

Transport: Whole blood at room temperature (20-25°C or 68-77°F), or plasma obtained through the process listed above, frozen (-20°C/-4°F or below).

Rejection Criteria

  • Glass tubes and 3.8% Sodium Citrate tubes.
  • Specimens that are clotted or grossly hemolyzed.
  • Inappropriate specimen volume.
  • Thawed or partially thawed specimens.


Monday - Friday, 7:00 a.m. - 3:30 p.m.
Results available the next business day.

Reference Range


Test Methodology

Change in Optical Absorbance (IL ACL TOP Series).


Low levels indicate Factor II deficiency, liver disease, Vitamin K deficiency, Coumadin therapy, or antibody induced deficiencies (lupus-like anticoagulant).

Clinical Utility

This assay aids in the diagnosis of congenital deficiency (rare). This assay also aids in the evaluation of acquired deficiencies associated with liver disease or vitamin K deficiency, oral anticoagulant therapy, antibody-induced deficiencies (e.g., in association with lupus-like anticoagulant). It is used in determining warfarin treatment stabilization in patients with nonspecific inhibitors (i.e., lupus anticoagulant) and in determining the degree of anticoagulation with warfarin to correlate with the level of Protein S. This assay also aids in the investigation of a prolonged PT/PTT.

CPT Code


Test Codes

Antrim #26120, EPIC: LAB5179, SOFT: FII

Last Updated


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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.