Plasma Thromboplastin Component (PTC) Potency of Plasma Fractions.

Abstract
The plasma thromboplastin component (PTC) factor is concd, in fractions III and IV-1 of the plasma proteins. Small quantities are found in fractions I and IV-4, none in fractions II and V. Since fraction II contains thrombin and fraction IV-1 is poorly soluble, neither is suitable for intraven. administration. The intraven. administration of fraction IV produced marked shortening of the whole blood coagulation time and reduction in residual serum prothrombin in PTC deficiency. The results appear superior to those which can be achieved by the intraven. administration of fraction I in hemophilia.