title: Standard for human thrombin.
abstract: Ten laboratories took part in an international study of the proposed standard for human thrombin. A freeze-dried preparation (coded 70/157) was shown, using clotting time tests, to be suitable to serve as a standard for the assay of human and bovine thrombin preparations. The study shows that assay variation within laboratories was much less than between laboratories. The preparation was stable, having a negligible estimated loss of potency after ten years under the recommended storage conditions (--20 degrees C in the dark). Each ampoule of the standard was assigned a potency of 100 units of thrombin activity, and one unit was defined as the activity contained in 0.0853 mg of the freeze-dried preparation. It was agreed by the participants in the study and by the International Committee on Thrombosis and Haemostasis (Vienna, 1973) that the thrombin preparation coded 70/157 is suitable to serve as an international standard for human thrombin.
mesh_terms: D000818:Animals; D002417:Cattle; D004355:Drug Stability; D004356:Drug Storage; D005340:Fibrinogen; D005612:Freeze Drying; D006801:Humans; D007202:Indicators and Reagents / Q000592:standards; D007391:International Cooperation; D007753:Laboratories / Q000592:standards; D013696:Temperature; D013917:Thrombin / Q000592:standards*; D006113:United Kingdom; D014894:Weights and Measures
chemical_list: D007202:Indicators and Reagents; D005340:Fibrinogen; D013917:Thrombin