AllMagTM Superparamagnetic Polymer Nanospheres have a core-shell structure of magnetite-rich core and polymer shell. These nanoparticles are modified to provide carboxyl groups permitting the covalent attachment of proteins or ligands onto the surface of the nanoparticles, and can be used for protein extraction, affinity chromatography, cell isolation, Immuno-chromatography test and clinical diagnostic, etc.