in accordance with the present invention , there are provided methods for the separation of biological materials employing a variety of polymeric materials with defined chemical , physical and mechanical properties . thus , a wide range of biological materials can be separated according to the present invention . polymeric materials contemplated for use in the practice of the present invention are block copolymers of partially hydrolyzed acrylonitrile which have excellent storage stability , are chemically inert , contain minimal residual concentration of monomeric species , and can be prepared in large scale .