Factor VIII, Activity
Also known as: F8
Use
This test is used to diagnose hemophilia A or acquired factor VIII deficiency, or as part of a diagnostic workup for von Willebrand disease (VWD). It may also be used to monitor treatment in individuals with factor VIII deficiency or VWD. It is not recommended for screening thrombophilia, which requires different diagnostic approaches.
Special Instructions
Separate specimens must be submitted if multiple tests are ordered. Use sodium citrate (Lt. blue) tubes. Refer to Specimen Handling guidelines for hemostasis/thrombosis at aruplab.com. Collected specimens must be processed to obtain platelet-poor plasma.
Limitations
The test is not recommended for thrombophilia screening purposes. Analytical results may be impacted by inappropriate specimen handling and collection procedures, such as hemolysis or use of incorrect anticoagulants. The results must be interpreted in the context of each patient's clinical condition and history.
New York Approved
Methodology
Automated Analyzer (Coagulation)
Biomarkers
LOINC Codes
- 3209-4
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 blood in a Lt. blue (sodium citrate) tube and process to obtain platelet-poor plasma.
Storage Instructions
CRITICAL FROZEN. Specimens must be separated when multiple tests are ordered.
Causes for Rejection
Serum, EDTA plasma, clotted or hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |
| Refrigerated | Unacceptable |
| Frozen | 3 months |
Other tests from different labs that may be relevant