» Antithrombin III is an inhibitor of plasma serine proteases. The most important function of
Antithrombin III is to inhibit thrombin activity.
» Heparin is used to increase the rate of thrombin inhibition several thousand fold.
» The assay is a two step process.
» In the first step, Thrombin is added to the plasma (diluted with an excess of heparin).
» In the second step, following the initial incubation period residual thrombin activity
is determined through the addition of SPECTROZYME® TH, a thrombin-specific
» The residual thrombin activity is inversely proportional to the Antithrombin III concentration.