The complete purification of human leucocyte interferon

Abstract

Human leucocyte interferon (HuLeIF) has now for the first time been purified by a series of techniques involving precipitation, gel filtration, and affinity chromatography with Cu-chelate, blue dextran, and antibody. The two major species of HuLeIF were identified as two clearly separable and stainable proteins representing 85% of the biological activity with molecular weights of 18,400 and 20,180 daltons. Three more subspecies of HuLeIF were demonstrated with molecular weights of 19,500, 20,900 and 22,130 daltons, representing 15% of the biological activity. Specific activity of pure interferon is 2 x 10(9) interferon units/mg protein. Recovery was about 50%, and the purification factor exceeded 350,000.