Separation medium for chromatography of various biomolecules

A method for biomolecule separation comprising applying a sample to a separation medium, comprising an inner core of a porous material provided with charged ligands, and an outer lid comprising a porous material provided with charged ligands, wherein the charge of the ligands in the inner core is opposite that of the charge of the ligands in the lid, wherein large biomolecules are prevented from entering the separation medium by charge repulsion from the separation medium and small biomolecules are captured in said inner core.

The method of 22, wherein the porosity of the lid is such that biomolecules larger or equal to a molecular weight of 20 000, preferably 50 000 or 100 000 g/mol are excluded, and the porosity of the inner core is larger than the lid porosity.