Antithrombin III Activity with Reflex Antigen

Message

Following standard venipuncture techniques, collect blood in a light blue-top tube containing 3. 2% sodium citrate, mix gently by inverting 3-4 times.

Test Code

LAB9871 AT3AR

Alias/See Also

AT3AR

CPT Codes
85300

Includes

@BKRCERMSGREFRESH(2302793)@ @BKRCERMSGREFRESH(2302794)@

Instructions

Processing Instructions (Lab use only): Please submit a separate, frozen vial for each special coagulation assay ordered.Centrifuge for 15 minutes within one hour 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 1.0 mL platelet-poor plasma into 2 new plastic vials. Freeze immediately. Minimum Testing Volume: 0.5 mL (x2) Platelet poor plasma Transport Temperature: Frozen Stability: Ambient: N/A Refrigerated : N/A Frozen: 30 days Causes for Rejection: Gross hemolysis Gross lipemia Gross icterus

Report Available

5-Days

Clinical Significance

1230171189

Last Updated: May 18, 2026

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.