<unk>  <unk>  is a blood test used to detect deficiency or abnormalities in fibrinogen, especially in cases of heparin contamination.<unk> , an enzyme found in the venom of Bothrops snakes, has activity similar to thrombin. Unlike thrombin,<unk>  is resistant to inhibition by antithrombin III. Thus, the<unk>  is not prolonged in blood samples containing heparin, hirudin, or direct thrombin inhibitors, whereas the thrombin time will be prolonged in these samples.<unk>  also differs from thrombin by releasing fibrinopeptide A, but not fibrinopeptide B, in its cleavage of fibrinogen. + Causes of prolonged thrombin time<unk>  Cause Further workup indicated Normal Heparin, hirudin, or direct thrombin inhibitor Human TT and/or heparin assays Prolonged Hypo- or afibrinogenemia Fibrinogen quantification Dysfibrinogenemia Fibrinogen activity assay Fibrin(ogen) split products (FSP) FSP or D-dimer quantification
Reptilase time
Thrombin time
Activated clotting time
Partial thromboplastin time
Coagulation activation marker
Prothrombin time
Ecarin clotting time
Kaolin clotting time