Factor X, Chromogenic
Also known as: Stuart Factor, Stuart Prower Factor
Use
The chromogenic factor X activity test can be useful in monitoring patients on vitamin K antagonist therapy where baseline PT is prolonged.
Special Instructions
If the patient's hematocrit exceeds 55%, adjust the volume of citrate in the collection tube accordingly. Refer to Coagulation Collection Procedures for detailed directions. Ensure proper blood-to-anticoagulant ratio by filling evacuated collection tubes completely. Use a discard tube only when using a butterfly collection system.
Limitations
This assay should not be used for monitoring heparin or oral direct factor Xa inhibitors such as rivaroxaban, apixaban, or edoxaban. The assay is not dependent on thromboplastin or fibrinogen, making it insensitive to lupus anticoagulants.
Methodology
Other
Biomarkers
LOINC Codes
- 28657-5
- 28657-5
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion, mixed immediately by gentle inversion. If using a winged collection set, draw a discard tube first. Centrifuge and transfer plasma into a Labcorp PP transpak frozen purple tube, freeze immediately.
Storage Instructions
Freeze.
Causes for Rejection
Gross hemolysis; clotted specimen; frozen specimen thawed in transit; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 28 days |