Methods for the preparation and ultraviolet irradiation of human fibrinogen for intravenous use.

A procedure is described for the purification and sterilization of human fibrinogen obtained as Fraction I by the ethanol fractionation method of Cohn, et ah Fraction I is redissolved, clarified, and treated with ultraviolet radiation in the presence of cysteine to destroy possible bacterial and viral contaminants, including the agent or agents of viral hepatitis. It is then reprecipitated by ethanol. Final solution is made in a buffer containing citrate, chloride, and glucose, and sterilization is accomplished by Seitz nitration. The finished product is obtained by dispensing, aseptically, the sterile bulk solution into sterile bottles, shell freezing, and drying from the frozen state. The dried product is characterized by a clottable protein content of 80 to 90 per cent.