Factor II, Activity (Prothrombin)
Also known as: F2
Use
This test evaluates possible factor II deficiency, known as prothrombin deficiency, which is a rare bleeding disorder caused by low levels of prothrombin, a protein necessary for blood clotting. It is used to assess the prothrombin activity levels in the blood and helps in diagnosing bleeding disorders. This test is different from prothrombin variant testing, which looks for inherited thrombotic risk factors.
Special Instructions
This test should not be ordered for prothrombin mutation testing. Separate specimens must be submitted when multiple tests are ordered. For specific hemostasis/thrombosis specimen handling guidelines, refer to ARUP's website.
Limitations
The test cannot be used to detect prothrombin mutations like the G20210A pathogenic variant, which requires a different assay. Serum, EDTA plasma, clotted, or hemolyzed specimens are unacceptable and will lead to rejection, potentially causing delays in diagnosis. There may be cross-reactivity with some anticoagulants, affecting coagulation testing results.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 3289-6
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
1 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Collect in a Lt. blue (sodium citrate) tube. Transfer 2 mL platelet-poor plasma to the transport tube. Refer to ARUP's specimen handling guidelines for detailed collection instructions.
Storage Instructions
Critical to keep frozen. Ambient temperature stability is up to 4 hours; refrigerated conditions are unacceptable.
Causes for Rejection
Serum, EDTA plasma, clotted or hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |
| Refrigerated | Unacceptable |
| Frozen | 2 weeks |