Neutralization of TRIC organisms by antibody: enhancement by antisera prepared against immunoglobulins

The neutralizing activities of fowl, rabbit and mouse antisera prepared against TRIC agents were enhanced, in some cases over a 100-fold, by the addition of antiserum against the appropriate IgG. Significant non-specific inactivation of the organisms was observed in the absence of antiserum against TRIC agents, in reaction mixtures containing normal serum and antiserum against IgG. Since the extent of this inactivation showed a prozone, control tests with dilutions of normal serum equivalent to the full range of dilutions of the antiserum tested are necessary to show that enhancement of neutralization is specific.