Enzyme fractionation and simultaneous nucleic acid removal from crude cellular extracts by preformed gradient ion exchange gel filtration

A crude cellular lysate (S30) can be fractionated on DEAE Sephadex A-25 gel into major classes including an excluded protein class. The protein class itself can be fractionated simultaneously by applying a salt gradient to the A-25 gel before applying sample. The procedure is rapid, that is, complete in one column liquid volume (or less) of column development. In addition, the fractionating conditions are very mild permitting very high recovery of input enzyme activity in a volume representing minimal dilution of the original sample.