Abstract
The ratio of fibrinolytic to proteolytic activity of human plasmin, in more purified systems, is of the same order as that shown by trypsin and chymotrypsin. Streptokinase, in the presence of minute amts. of human plasminogen or human plasmin, activates the bovine plasminogen contaminating the bovine fibrinogen in the fibrinolytic assay. The fibrinolytic assay for streptokinase activated human plasmin, as presently employed with bovine fibrinogen and thrombin, measures the activator function of the human enzyme rather than the fibrinolytic activity of the human plasmin.