INFLUENCE OF ELECTROSTATIC FORCES ON IGG ADSORPTION ONTO POLYSTYRENE BEADS

Some electrostatic aspects of the interaction between rabbit immuno gamma globulins (IgG) and positively and negatively charged polystyrene (PS) beads are reported. Adsorption and electrophoresis experiments have been performed as a function of pH and ionic strength. Both polystyrene beads reached a maximum adsorption around pH 6.0. The isoelectric points of the IgG-PS complexes were 6.0 and 8.0 for the anionic and cationic latices, respectively. This difference indicates that the charge of the PS beads at least partially compensates the net charge of the IgG molecules. The influence of electrostatic forces on protein adsorption has been studied by investigating the ability of adsorbed proteins to be displaced by an increase in ionic strength. Finally, the ionic strength effect on electrophoretic mobility of the sensitized cationic polystyrene beads has been analyzed.