Procedures for coating ultrafine particles of iron with synthetic polymers were developed. The magnetic particles were covered with synthetic polymers such as polymethyl methacrylate, polystyrene, polyacrolein or their mixtures. Those polymers are containing functional groups that can be covalently bonded to protein and biochemically active substances.
At an initial step of the modification, surface hydroxyl groups of iron particles were reacted with silane coupling reagent which can be copolymerized with vinyl monomers.
Polymer coated particles were conjugated with immunoglobulins, protein A, bovine serum albumin or glucose oxidase. Those coated ultrafine particles can bind proteins up to 20% of their weight. In addition, those particles are well dispersed in aqueous solutions upon sonication and still magnetically active. Those particles may be useful for immobilization of enzyme or for magnetic affinity chromatography of cell and its organella.