Localization of antigens in thin sections of bacteria by the immuno-peroxidase technique

The immunoperoxidase technique together with electron microscopy has been examined for the ultrastructural localization of staphylococcal protein A, the immunoferritin method being included for comparison. The results show that protein A is uniformly distributed in the whole cell wall. Both the direct and indirect methods, Fab- as well as Fc-reactions, showed identical results. tthe immunoperoxidase method was superior to the immunoferritin method, especially when applied to thin sections of the bacteria, and the clear specificity demonstrated indicates a useful method for localization of cellular antigens.