Preparation of antihemophilic factor from indated plasma.

Four large-scale batches of Antihemophilic Factor (AHF, factor VIII) were prepared from plasma derived from 4 to 6-day-old blood applying a method developed for preparation of AHF from fresh frozen plasma. The AHF product was 6 to 9-fold concentrated over plasma with 7 to 10-fold purification and a recovery of 100 to 140 factor VIII units per liter of starting plasma. In terms of purity and yield, this is about half that of AHF obtained from fresh frozen plasma. The AHF concentrate was free of detectable thrombin and plasmin and the solubility of the dry product was comparable to that of the product derived from fresh plasma but the hemoglobin content was slightly increased. After further fractionation with polyethylene glycol (PEG 4000), a highly soluble AHF product 100-fold purified, and 30-fold concentrated, was obtained with 60% factor VIII recovery, which corresponds to a final yield of 60 to 85 factor VIII units per liter of starting plasma.