The ecarin chromogenic assay (ECA) determines the direct thrombin inhibitor (DTI) concentration in plasma without interference from abnormal prothrombin or fibrinogen levels. ECA results are independent of coagulation factors and plasmatic inhibitors within the sample. As it is not influenced by lupus anticoagulants, the assay allows for specific determinations. ECA is insensitive to heparin, LMWH, danaparoid, fondaparinux, and direct factor Xa antagonists. The wide measuring range includes two reagent formats dedicated to each DTI type (ECA-H for recombinant hirudins, ECA-T for synthetic DTIs). Specific standards and controls are also available.