Monodispersed microspheres with polystyrene as the core and poly（acrylamide-co-N-acryloxysuccinirnide） as the shell were synthesized by a two-step surfactant-free emulsion copolymerization.The core-shell morphology of the microspheres was shown by scanning electron microscopy and transmission electron microscopy.Rabbit immunoglobulin G （as antigen） was covalently coupled onto the microspheres by the reaction between succinimide-activated ester groups on the shell of the microspheres and amino groups of the antigen molecules.The size of particles was characterized by dynamic light scattering technique and was found to vary upon bioconjugation and interaction with proteins.The binding process was shown to be specific to goat anti-rabbit immunoglobulin G（as antibody） and reversible upon the addition of free antigen into the system.
