Abstract: Methods are provided for purification of Factor VIII polypeptides by immunoaffinity chromatography and ion exchange chromatography, in which the eluate from the immunoaffinity column is diluted with a solution comprising higher salt concentration, or lower non-polar agent concentration than that of the elution solution, prior to passing the diluted solution through the ion exchange column. The methods result in improved purification without significant yield loss.

Abstract: Methods are provided for purification of Factor VIII polypeptides by immunoaffinity chromatography and ion exchange chromatography, in which the eluate from the immunoaffinity column is diluted with a solution comprising higher salt concentration, or lower non-polar agent concentration than that of the elution solution, prior to passing the diluted solution through the ion exchange column. The methods result in improved purification without significant yield loss.

Abstract: Methods are provided for purification of Factor VIII polypeptides by immunoaffinity chromatography and ion exchange chromatography, in which the eluate from the immunoaffinity column is diluted with a solution comprising higher salt concentration, or lower non-polar agent concentration than that of the elution solution, prior to passing the diluted solution through the ion exchange column. The methods result in improved purification without significant yield loss.

Abstract: Processes for improving the in vivo function of factor VIII by shielding exposed targets of the factor VIII comprise a) immobilizing the factor VIII by interaction with a group-specific adsorbent carrying ligands manufactured by organic-chemical synthesis, for preventing polymer coupling to reactive amino acids of the immobilized factor VIII, within or adjacent to interaction domains; b) activating a biocompatible polymer; c) conjugating the activated biocompatible polymer to external sites of the immobilized factor VIII; and thereafter d) eluting the conjugate from the adsorbent. Processes for administering factor VIII comprise subcutaneously, intramuscularly, intradermally or intravenously administering a conjugate of factor VIII and a biocompatible polymer, and methods for treatment of hemophilia A comprise subcutaneous, intramuscular, intradermal or intravenous administration of a conjugate of factor VIII and a biocompatible polymer.