Technoclot® PT Plus is a plain prothrombin time (PT) reagent according to the method of Quick. The reagent is lyophilized and contains rabbit brain thromboplastin and a solvent containing calcium. Technoclot® PT Plus is sensitive to decreased factors II, V, VII, X and fibrinogen levels but insensitive to heparin. Technoclot® PT Plus is a “low” ISI-reagent with an ISI of about 1.2. Technoclot® PT Plus can be used as a research tool for the extrinsic coagulation system, as a liver function research test and as a control in oral anticoagulant research.