Whole antiserum versus the gamma-globulin fraction of antiserum in the indirect fluorescent antibody technique.

Two antisera were compared with their γ-globulin fractions for their effectiveness as the middle or unlabelled layer in the indirect fluorescent antibody technique. The γ-globulin fraction did not produce better results in either case than the equivalent concentration of whole serum. Control sections were prepared with normal rabbit serum substituted for the whole antiserum and with normal rabbit γ-globulin substituted for the γ-globulin fraction of the antiserum. The control sections with γ-globulin showed considerably more non-specific fluorescence than those with whole serum. In one case the non-specific fluorescence in the γ-globulin control interfered with interpretation of the experimental section.