Abstract: Highly purified, biologically active Human Factor VIII:C having specific activities of about 4000-8000 units per milligram of protein is prepared. In the method of preparation, an AHF concentrate is solubilized or equilibrated in an aqueous medium and treated to change the effective Stokes' radius of the Factor VIII:C to an apparently low value and then subjected to a separation from the concentrate. Treatment of the highly purified Factor VIII:C with a mixture of glycosidases causes substantial removal of carbohydrate side chains without reduction of procoagulant activity and with retention of significant in vivo survival time.

Abstract: Highly purified, biologically active Human Antihemophilic Factor (AHF) preparations are prepared having specific activities of about 4000-8000 units per milligram of AHF. In the method of preparation an AHF concentrate, prepared by fractionation of plasma to partially remove fibrinogen, fibronectin and other plasma components is subjected to a separation on the basis of Stokes' radius to separate AHF from the bulk of remaining proteins in the AHF concentrate. The pooled fractions containing AHF activity are concentrated by precipitation with ammonium sulfate, sodium sulfate, etc., by diafiltration, by PEG addition, or the like. The concentrate, is solubilized or equilibrated in an aqueous medium and treated to change the effective Stokes' radius of the AHF to an apparently low value and then subjected to a separation from the concentrate. The AHF pool from above is treated to remove cations by dialysis against an appropriate buffer of lower ionic strength and chromatographed on an anion-exchange medium.