Improved techniques for the fractionation of non-histone proteins of chromatin on hydroxyapatite

The effect of the dissociation medium on the fractionation of chromatin on hydroxyapatite has been studied. Optimal separations of the histones and non-histone protein are only achieved when columns are run in buffers containing high concentrations of sodium ions. We have modified our previously published method such that the chromosomal proteins can be recovered in virtually quantitative yields. Each of the hydroxyapatite fractions has been analysed with respect to nucleic acid content and the proteins have been analysed by two-dimensional gel electrophoresis.