The demonstration of urokinase antigen in whole blood

Abstract

Using a monospecific immunoprecipitating antiserum to urinary urokinase, the presence of a protein immunologically indistinguishable from urinary urokinase has been demonstrated in plasma and serum. The concentration of this material in normal plasma and serum ranges from 3 – 12μg of protein/ml by comparison with an active urokinase standard of specific activity 20,000 Ploug units (P.U.)/mg protein. The level of urokinase antigen in blood was unrelated to the 24 hour excretion of urinary urokinase in normals.