Update Type: Test Resumed
Test Updated: 08/24/2022
Test Overview
Test Methodology

Optical detection of clot formation in the Dilute Russell's Viper Venom Time (DRVVT).

Test Usage

Activated Protein C Resistance is associated with a point mutation in the Factor V gene. This mutation slows the inactivation of factor Va by APC causing a hypercoagulable state.

Reference Range *

Ratio greater than or equal to 1.8

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

Test Limitations

Initial oral anticoagulant treatment before stabilization and levels of Protein C below 50% may give low APCR ratios.

Test Details
Days Set Up
Analytic Time

1 hour

Soft Order Code
MiChart Code
APC Resistance
  • APC Resistance
  • APCR
  • Factor V Leiden Mutation Screen
  • Protein C Resistance, Activated
  • Factor 5 Leiden Mutation Screen
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 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 2.7 mL tube or 1 mL plasma aliquot
Minimum Volume
Full 1.8 mL tube or 1 mL 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, or grossly hemolyzed.
Additional Information

Samples with positive or borderline results should be confirmed by genetic analysis as Factor V Leiden is
a genetic mutation.

CPT Code
Fee Code