Test Overview
Test Methodology

Real-Time Polymerase Chain Reaction (PCR) with Allelic Discrimination Analysis

Test Usage

This test is used for identifying patients who may require warfarin (Coumadin) dosing adjustments including: patients who are receiving warfarin for the first time; patients who have required multiple dosing adjustments to maintain the international normalized ratio (INR) in the target range; and patients with a history of thrombosis or bleeding when taking warfarin.

Reference Range *

Interpretive report provided.

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

Test Details
Days Set Up
Monday - Friday
Analytic Time

3 - 12 days

Soft Order Code
  • Warfarin Sensitivity Analysis
  • WARF
  • Cytochrome P450 2C9 Genotyping
  • Vitamin K Epoxide Reductase C1 Genotyping
  • CYP450 Genotype
  • VKORC1 Genotype
  • CYP2C9 Genotype
Reference Laboratory
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in a lavender top (EDTA) tube. Send intact specimen at room temperature within 24 hours of collection. Saliva: Saliva Swab collection kit should be used. DNA: 100 mcL at a concentration of 50 ng/mcL

Normal Volume
3 mL EDTA whole blood
Minimum Volume
0.5 mL EDTA whole blood
Additional Information

Test sent to Mayo Medical Laboratories.

CPT Code