Antihaemophilic factor (factor VIII) from human granulocytes.

Factor VIII has been isolated and purified from human granulocytes using chromatography on Sephadex G-200 AND DEAE-Sephadex A-50. The final preparation was purified 60-fold. Some properties of this partly purified factor VIII were compared with the human plasma AHF preparation. Optimum pH activity and the highest activity after incubation at different pH values was found in buffer at pH 7.0. The preparation was thermolabile and had a molecular weight of about 214,000. Absorption curves indicated that it is a protein exhibiting four fractions in polyacrylamide gel disk electrophoresis. AHF preparations from plasma and granulocytes were almost identical in the characteristics tested.