Protein A‐gold electron microscopic immunocytochemistry: Methods, applications, and limitations

Abstract

Abstract The postembedding protein A‐gold immunocytochemical approach has been introduced as an alternative to other techniques for the ultrastructural localization of antigenic sites. The present review deals with the development, the theoretical background, and technical approach of the protein A‐gold method as well as the different modifications introduced in order to enhance the resolution of the results and to perform double labelings on the same section. Various examples demonstrate the reliability and the wide range of application of this technique. In addition, some problems, pitfalls, and limitations particular to this method are reported.