[Characteristics of the precipitation reaction at the stage of antigen-antibody complex aggregate formation studied by a spectroturbidimetric method].

The possibility of using the spectroturbidimetric method, one of the variants of the light scattering method, for the determination of the characteristics of the second phase of the antigen-antibody reaction was shown examplified by the interaction between rabbit antiserum and bovine serum albumin. The parameters of the aggregates formed in the process (their average size, their concentration by weight and number) were calculated for the whole period of the reaction and with its components taken in different proportions. The precipitation curve plotted by the above method correlated well with the result of an independent determination at an extinction coefficient of E278. A conclusion was drawn, based on special evaluation, that hydrophobic interactions have a predominant influence on the formation of antigen-antibody aggregates. A quantitative approach was proposed for studying the mechanism of the antigen-antibody aggregate formation and for the analytical determination of various classes of immunoglobulins.