The ion-exchange materials carry ionizable groups which are attracted to the ions of opposite charge to form salts in the presence of suitable buffers. A mixture of proteins is passed through the column of the ion-exchanger in a glass tube, which binds to the column. Different buffer solution or eluting agents or varying pH are then poured over the column and washed off at different times. The eluting agents may be solution of increasing salt concentration of buffer of increasing pH. By increasing the pH of eluent, different fraction of proteins are obtained .