A primary aspect of the present invention relates to a method for the fractionation of a protein-containing mixture, said method comprising the steps of: a) optionally adjusting the pH of the mixture b) applying said mixture to an adsorption column comprising an adsorbent, said adsorbent comprises a particle with at least one high density non-porous core, surrounded by a porous material, the adsorbent having a particle density of at least 1.5 g/ml and a mean particle size of at most 150 mu m c) optionally washing the column d) eluting at least one protein from the adsorbent.
