A large scale procedure for isolation of the glycine-rich, arginine-rich histone and the arginine-rich, lysine-rich histone in a highly purified form.

1. A procedure is presented for large scale fractionation of arginine-rich histones by exclusion chromatography. With this method, 2 to 3.5 g of histone Fractions 2a and 3 were fractionated. The two fractions contained the same histone components, but they differed in the amounts of each component. 2. In histone Fraction 2a, the glycine-rich, arginine-rich (GAR) histone accounted for approximately 70% of the protein present. This histone was obtained in a highly purified form after exclusion chromatography was repeated once, as shown by polyacrylamide gel electrophoresis, amino acid analysis, and peptide maps. Rechromatography of this product on Sephadex G-25 provided a GAR histone which was 96% pure. A quantity of GAR histone of 1 g was readily isolated by this procedure. 3. In histone Fraction 3, the arginine-rich, lysine-rich (AL) histone accounted for approximately 60% of the protein present. Rechromatography of the AL histone on Sephadex G-100 followed by rechromatography on Sephadex G-25 and Sephadex G-200 yielded a product approximately 96% pure. As in the case of the GAR histone, 1 g of the AL histone was readily obtained.