Magnetic nanoparticles have have become very important in many applications including high density data storage, magneto-optical switch, magnetic resonance imaging, drug delivery and targeting.Several functional nanomagnetic particles are prepared for biochemical applications using a modified magnetapheresis.This separation method is based on affinity reaction between surfaces of magnetic and magnetic nanoparticles for biochemical analysis.In this method, magnetic nanoparticles labeled with antibody are flowed through a thin separation channel to form depositions for selective capturing samples with specific antigen due to the specific affinity interaction.