[Sensitivity of several commercial thromboplastins to non-carboxylated clotting factors II and X (author's transl)].

All reagents for determination of thromboplastin time (Quick-test) tested so far are sensitive to non-carboxylated clotting factor X, and sensitivity varies, depending on the reagent. The thromboplastins of Behring and Thrombotest are very sensitive. The preparations of La-Roche and Boehringer are somewhat more sensitive than those of Dade and Goedecke. Only the differences between the first group (Behring, Thrombotest) and the others are significant. There is a good correlation between factor X sensitivity, prothrombin time and non-carboxylated clotting factor X sensitivity, with all reagents. These results may be of significance for quality control and standardization of the prothrombin time.