Chemical modification of polystyrene's surface and its effect on immobilized antibodies

The quantity and immunoreactivity of antibodies coupled to treated polystyrene beads were studied as a function of the chemical treatments used to prepare the polystyrene surface. Injection-molded polystyrene beads were nitrated with sulfuric and nitric acids followed by reduction to form amine groups. The nitration conditions used affect the quantity of nitro and amine groups introduced, and ultimately the quantity of antibody coupled to the surface. Aminated beads were also grafted with monomethoxypolyethylene glycol (mPEG) prior to antibody coupling to determine if this modification could lower non-specific protein binding to the beads. At high surface levels of mPEG, antibody coupling was completely blocked. At lower surface levels of mPEG, antibody coupling was accomplished, but with no reduction of the non-specific protein binding to the beads. (C) 1998 Elsevier Science B.V.