Antithrombin III Activity : 216

Test Code

AT3ACT or 216

CPT Codes
85300

Instructions

Submit a separate frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate. Mix gently by inversion 3-4 times. Centrifuge light blue-top tube for 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 (<10,000/mcL). Freeze immediately and ship on dry ice.

Transport Container

Preferred Specimen
1 mL frozen platelet-poor plasma collected in 3.2% Sodium citrate (light blue-top) tube

Minimum Volume
0.5 mL

Transport Temperature

Frozen.

Specimen Stability

Room temperature: Unacceptable; Refrigerated: Unacceptable; Frozen: 30 days

Methodology
Chromogenic Substrate

Setup Schedule

Monday - Friday

Report Available

1-5 days

Reference Range

1 day - 1 month 41-108 % normal
31 days - 2 months 50-120% normal
3-5 months 73-120% normal
≥ 6 months 80-135% normal

Clinical Significance

Aids in the detection of hypercoagulable states associated with venous thrombotic episodes. May be useful in patients who appear to be hyporesponsive to heparin.

Performing Laboratory
med fusion

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.