<p>A process for a combined dual step separation of a mixture of two or more groups of molecular substances where the groups differ in their ability to be transported into and bound by two capture media, such that members of one group are largely excluded from the first media allowing them to flow through' to the second media is disclosed The capture media may both be based on similar base matnces and ligands but differ in other properties Examples of mixtures for processing in this manner include native and polysaccharide modified proteins, or native and synthetic polymer modified proteins The groups of molecules may themselves be heterogenous in regard to properties other than the above interactions This includes a group of monopolymer grafted proteins of protein to polymer molar ratio 1, whose members are heterogenous in regard to the position of polymer coupling to the protein</p>
