Accelerator-Globulin and Prothrombin: Preparation of Accelerator-globulin Free Plasma.

Abstract

A method has been devised whereby plasma can be rendered free of Ac-globulin. The product contains 50-100 units of prothrombin. The procedure consists of treating fresh oxalated beef plasma, previously frozen and thawed, with 17 g./100 cc. of kaolin. The kaolin-plasma is frozen 24 hours, thawed, and cen.trifuged. The supernatant is treated with equal volumes of 1.5% bichloride of mercury, and insoluble, coagulated egg albumin added. The mixture is centrifuged, and the supernatant defibrinated, filtered, and stored at -40[degree]C. The amount of Ac-globulin in any given plasma is manifested as a function of 3 variables: (1) the time when conversion begins, (2) the rate of conversion, and (3) the thrombin yield. The quantitative measure of Ac-globulin, which includes the variables, can be represented by an area which is circumscribed by the activation curve and by straight lines through a constant, arbitrarily selected point on each axis. This area can be measured with a planimeter, and the amount of Ac-globulin of an unknown be compared with that of the normal control. By referring the area to a standard reference curve, the Ac-globulin activity can be expressed in percent of normal.