Magnosphere™ MS160/Tosyl & MS300/Tosyl are magnetic particles especially for high purity bioseparation. The surface of these particles are coated with hydrophilic polymer for reducing non-specific binding and are activated with p-toluene sulfonyl (tosyl) group. The Tosyl group enables to immobilize ligands such as antibody without using coupling reagents.The activated Tosyl group is eliminated though a coupling reaction, the surface of the particles became hydrophilic to reduce non-specific binding. Uniform particle size and superparamagnetic property of the Magnosphere™MS160/Tosyl & MS300/Tosyl provide good magnetic separation and re-suspension response.