Partial Thromboplastin Time, Activated

What it measures

• Partial Thromboplastin Time, ActivatedLOINC 14979-9

Specimen

Specimen

One full unopened 3.2% sodium citrate (light blue-top) tube

Minimum volume

0.3 mL

Also accepted

1 mL frozen plasma

Container

3.2% sodium citrate (light blue-top) tube

Temperature

Room temperature

Unopened light blue-top tube: Correct ratio of blood to citrate is critical. Do not overfill or underfill collection tube. Mix by inversion 4 times. For non-heparinized patients, maintain specimen at room temperature. Do not uncap. Stable 24 hours at room temperature. Platelet-poor plasma: Centrifuge light blue-top tube 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (Freeze immediately and ship on dry ice. Whole blood: The tubes should be at 100% +/- 10% fill volume in order to obtain the correct ratio.

Turnaround

Set up: Daily (Day shift and Night shift); Report available: 2 days

Billing

CPT 85730