1 hour
Test Updated:
Antithrombin III Assay, Functional
Serine Protease Inhibitor
AT3
ANTITHROMBIN III ACTIVITY
Factor 10a Inhibition
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Test Overview
Chromogenic
AT3 levels are used as a possible indicator of hypercoagulability, and to test for the hereditary deficiency of antithrombin. AT3 levels might also be of use in cases of suspected heparin failure especially prior to heparinization.
75 - 125%
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Specimen Requirements
Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.
