Preparation and partial characterization of human plasma depleted of antithrombin-III by heparin-sepharose affinity chromatography

A simple and rapid method for the complete depletion of functional antithrombin-III from human plasma is described. The procedure involves affinity chromatography of pooled normal plasma on heparin-Sepharose equilibrated with 0.5M NaCl. Only antithrombin-III was removed by this procedure. The prothrombin time, activated partial thromboplastin time, and thrombin clotting time of the antithrombin-III depleted plasma were unchanged relative to the starting plasma. Plasma depleted of antithrombin-III contained no functional antithrombin-III, but contained 8 ug/ml of immunologically detectable antithrombin-III. Removal of this residual antithrombin-III by immunodepletion resulted in plasma which had an identical response to heparin as the plasma subjected only to heparin-Sepharose chromatography.