Test Overview
Test Methodology

Photo-optical clot determination with Factor X deficient substrate.

Test Usage

Detection of specific coagulation factor X deficiency.

Reference Range *

50-150% of normal activity.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

Increased in patients taking oral contraceptives. Interpretation of results may be limited if patient is receiving anticoagulant therapy.

Test Details
Days Set Up
Monday - Friday, one run per day
Analytic Time

1 hour

Soft Order Code
MiChart Code
Factor 10 Assay
  • Factor X Assay
  • Factor X:C Assay
  • F10
  • Factor 10 Assay
  • Factor 10 Activity
Specimen Requirements
Collection Instructions

Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a polypropylene plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.

This test is not indicated for inpatient evaluation of acute thrombosis.
Normal Volume
Full 2.7mL tube or 1mL plasma aliquot
Minimum Volume
Full 1.8mL tube or 1mL plasma aliquot
Storage Temperature
Room temperature for whole blood or frozen aliquot of citrated plasma.
Rejection Criteria
Specimens will be rejected if not properly filled, clotted, grossly hemolyzed, or contaminated with heparin.
Additional Information

Factor X may be increased in patients with nephrotic syndrome and decreased in patients with vitamin k deficiency, warfarin therapy, liver disease, factor X deficiency, multiple myeloma, or in the elderly with no apparent disease.

CPT Code
Fee Code