Test ID BLOD1075 Coagulation Factor X Chromogenic Activity Assay, Plasma
Reporting Name
Factor X Chromogenic Activity AssayUseful For
Monitoring warfarin anticoagulant therapy, especially in patients whose plasma contains lupus anticoagulants that interfere with baseline prothrombin time/international normalized ratio and in patients receiving the drug Argatroban who are being transitioned to warfarin
This assay should not be used for monitoring heparin, or oral direct factor Xa inhibitors such as rivaroxaban (Xarelto), apixaban (Eliquis), or edoxaban (Savaysa).
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Plasma Na CitSpecimen Required
Patient Preparation: Fasting preferred
Collection Container/Tube: Light-blue top (citrate)
Submission Container/Tube: Polypropylene vial
Specimen Volume: 1 mL
Collection Instructions:
1. For complete instructions see Coagulation Guidelines for Specimen Handling and Processing
2. Spin down, remove plasma, and spin plasma again.
3. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, at or below -40° C.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.
3. If priority specimen, mark request form, give reason, and request a call-back.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma Na Cit | Frozen | 14 days |
Reference Values
≥18 years of age: 60%-140%
Chromogenic Factor X activity generally correlates with the one-stage factor X activity. In full term or premature neonates, infants, and children, the one-stage factor X activity* is lower than adult reference range and progressively rises to the adult reference range by adolescence. However, no similar data for the chromogenic factor X activity have been published.
*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing.
Day(s) Performed
Monday through Friday
Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
85260
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Method Name
Chromogenic
Special Instructions
Secondary ID
89042Report Available
1 to 3 daysForms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.
Sanford Interface Build Information
Result Code | Result Code Description |
---|---|
5786 | Factor X Activity Chromogenic |