2 hours
Test Updated:
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
Chromogenic Substrate Assay
Monitoring warfarin anticoagulant therapy in patients whose plasma contains lupus anticoagulants and in patients receiving direct thrombin inhibitors.
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
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.
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.
