Days Set Up
Daily, 24 hours.
Analytic Time

2 hours

MiChart Code
Factor X Chromogenic Activity
Soft Order Code
CFX

Test Updated:

Synonyms

Factor 10 Chromogenic
Chromogenic Factor X Activity
CFX
Factor 10 Activity, Chromogenic
Factor 10 Chromogenic
INR Alternative
Factor 10 Chromogenic Activity

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Test Overview

Test Methodology

Chromogenic Substrate Assay

Test Usage

Monitoring warfarin anticoagulant therapy in patients whose plasma contains lupus anticoagulants and in patients receiving direct thrombin inhibitors.

Reference Range

A chromogenic factor X activity of approximately 20-40% corresponds to a 2.0-3.0 INR warfarin therapeutic range.

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

Specimen Requirements

Collection Onsite

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. 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.

Collection Offsite

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.

Blue Top Tube
Normal Volume
Full 2.7 mL tube or 1 mL plasma aliquot
Minimum Volume
Full 1.8 mL tube or 1 mL plasma aliquot

Billing Information

CPT Code
85260
Pro Fee Code
 
LOINC
33984-6

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.