Citrate buffer, antigen retriever has been used as a heat-induced antigen retriever on formalin-fixed paraffin-embedded (FFPE) tissue sections prior to application of antibodies or DNA fluorescent in situ hybridization.

In immunohistochemistry (IHC), most commonly used fixatives such as formalin mask tissue antigens (cellular, membrane, and nuclear) by their intrinsic crosslinking. This masking results in poor or no staining in IHC. The use of Citrate buffer, pH 6.0, or other antigen retrieval solutions on FFPE tissue sections improves accessibility of antibodies to tissue antigens.