Abstract: The invention is directed to a modified polysaccharide material which comprises: (1) polysaccharide covalently bonded to a synthetic polymer; (2) the synthetic polymer being made from (a) a polymerizable compound which is capable of being covalently coupled directly or indirectly to said polysaccharide, and (b) one or more polymerizable compounds containing (i) a chemical group capable of causing the covalent coupling of the compound (b) to an affinity ligand or a biologically active molecule or (ii) a hydrophobic compound.The invention is also directed to devices for the chromatographic separation of at least two components of a mixture comprising the modified polysaccharide material of the invention, wherein the device is configured for radial or tangential flow.