Abstract: High purity antithrombin III is recovered from a procedure in which the other protein fractions in human blood plasma are recovered for further processing. The protein fractions are recovered sequentially in separate steps: fibrinogen and Factor VIII are recovered as a precipitate; prothrombin complex is recovered on the surface of finely divided tricalcium phosphate; albumin and gamma globulin are recovered in an aqueous supernate; a protein precipitate containing lipids, lipoproteins and other trace protein contaminants is recovered; and antithrombin III is recovered as a precipitated phase. The fibrinogen, Factor VIII, prothrombin complex, albumin, gamma globulin and protein contaminants are all recovered in such a way that they are suitable for further processing.

Abstract: Lyophilizable, clottable fibrinogen free, Factor VIII is produced on a commercial scale from a fibrinogen containing Factor VIII concentrate by sequentially, precipitating a major portion of the clottable fibrinogen by the addition of an ethylene oxide-polyoxypropylene block copolymer, clotting the remainder of the clottable fibrinogen by the addition of a small amount of a thrombin mimetic enzyme which does not decrease the potency of the Factor VIII, and adding human albumin to the resultant clottable fibrinogen free Factor VIII to stabilize its potency during lyophilization.

Abstract: Hepatitis associated antigen is removed from plasma and plasma fractions by admixing the plasma with ethylene oxide-propylene glycol condensation product at a temperature of from about 0.degree. to 39.degree. centigrade. Under these conditions a precipitate is formed. The concentration of condensation product is adjusted so that all of the hepatitis associated antigen remains either in the precipitate or the liquid phase. Separation of the resultant liquid and solid phases produces a liquid phase which is entirely free of the undesired antigen. The concentration of condensation product which is required to cause complete precipitation of hepatitis associated antigen increases with increasing temperature from a value of about 9 percent, on a weight per volume basis, at about 0.degree. centigrades to a value of about 28 percent at about 39.degree. centigrade. All of the hepatitis associated antigen remains in the liquid phase at condensation product concentrations of less than about 7 percent at about 9.degree.

Abstract: Lyophilizable, clottable fibrinogen free, Factor VIII is produced on a commercial scale from a fibrinogen containing Factor VIII concentrate by sequentially, precipitating a major portion of the clottable fibrinogen by the addition of an ethylene oxide-polyoxypropylene block copolymer, clotting the remainder of the clottable fibrinogen by the addition of a small amount of a thrombin mimetic enzyme which does not decrease the potency of the Factor VIII, and adding human albumin to the resultant clottable fibrinogen free Factor VIII to stabilize its potency during lyophilization.