Specificity controls for immunocytochemical methods

Immunocytochemistry is used for antibody localization of proteins in cells and tissues. The specificity of the results depends on two independent crit eria: the specificity of the antibody and of the method used. The antibody specificity is best determined by immunoblot and or immunoprecipitation. Ab sorption of the antibody with a protein does not determine that the antibod y would have bound to the same protein in the tissue, and therefore is not a good control for antibody specificity. The specificity of the method is b est determined by both a negative control, replacing the primary antibody w ith serum, and a positive control, using the antibody with cells known to c ontain the protein. With the increasing use of immunocytochemistry, it is i mportant to be aware of the appropriate controls needed to show specificity of the labeling.