Present status of standardization in coagulation assays for control of oral anticoagulation

Recently, recommendations for the production of thromboplastins have been issued by International Committees (ICSH/ICTH) to achieve a standardization of prothrombin time assays. Following such recommendations we have standardized two new PT reagents based on coagulometric and photometric methods which rely on the same sensitive human placental thromboplastin. Both PT reagents have been optimized especially for use in oral anticoagulant therapy. They offer high sensitivity and reproducibility, accurate lot standardization and therefore internationally comparable values by the expression of the ISI value of each reagent batch.