Antigen retrieval, signal amplification and intensification in immunohistochemistry.

In this overview we emphasize new methods of improving immunohistochemical results in formaldehyde-fixed tissue samples. The benefit of heat-induced antigen retrieval in demasking of concealed epitopes is demonstrated. We provide guidance on the influence of heat-induced antigen retrieval in commonly applied monoclonal and polyclonal antibodies. Moreover, we show the promising methods of signal amplification using biotinylated tyramine and signal intensification of diaminobenzidine reaction products by metallic ions.