Antigen retrieval immunohistochemistry: Past, present, and future

The antigen retrieval (AR) technique, which is predominantly based on high-temperature heating of tissues, is used as a non-enzymatic pretreatment for immunohistochemical staining of formalin-fixed, paraffin-embedded tissue sections. It has been widely applied in pathology and analytical morphology. The existence of a growing body of literature on the AR technique raises a number of interesting issues for the further development of AR. These issues include the use of a 'test battery' and the concept of 'maximal retrieval' applied to the selection of optimal test protocols for the standardization of AR.