[Study of the kinetics of antigen-antibody reaction by light scattering]

Laser light scattering in conjunction with measurement of the spectral width and integral intensity of light scattering was applied to studying the process of complex formation of antigens and antibodies. The system of polysaccharide group A streptococcus and antibody against it was examined under varying polysaccharide concentrations. The measurements were performed every 10 s for 70 min after combining polysaccharide and antibody solutions. Within the entire time interval, the size of the complexes were less than the wave length of exciting laser light (0.633 m). This made it possible to determine their average magnitude in terms of the Rayleigh model.