Prothrombin Time and International Normalized Ratio (PT/INR)
Activated Partial Thromboplastin Time (aPTT)
This test is performed on a Sysmex fully automated coagulation system which utilizes optical detection technology.
The test is used to measure and evaluate how long it takes blood to clot, and bleeding or excessive clotting disorders. The INR is an international normalized ratio calculated from the PT and is used to monitor treatment in individuals taking the anticoagulant Warfarin.
Specimen Collection and Preparation
Collect a blood sample in the following tube:
Light Blue 3.2% Sodium Citrate Tube – Tube must be filled to 90% of minimum/maximum etched fill line
If possible, centrifuge the specimen at 3000 rpm for 15 min, remove plasma and freeze
Specimen Storage and Stability
Store whole blood at the following temperatures:
Room temperature: 24 hours
Refrigerated 2°C to 8°C: Unacceptable
Frozen: Separated plasma only.
Insufficient sample volume – Tube must be filled to with 90% of etched fill line
Sample not stored at proper temperature
Frozen whole blood
Severely lipemic specimens
Specimen labeled incorrectly or not labeled
Monday – Sunday, 16 hours a day
Result available within 24 hours of receipt in laboratory
NOTE: Specimens are refrigerated (2-8°) for 7 days before disposal
Vibra Health Laboratory
1307- A, Allen Dr Troy, MI 48083