title: Hypothesis for the mechanism for heat-induced antigen retrieval occurring on fresh frozen sections without formalin-fixation in immunohistochemistry.
abstract: The mechanism involved in heat-induced antigen retrieval (AR) remains unproven but probably utilizes the breaking of formalin-induced cross-linkages. We investigated the effectiveness of heat-induced AR on immunohistochemistry and dot-blot analysis using rat uterus tissue sections and protein extracts without formalin-fixation. The unfixed frozen sections, which did not show immunostaining with nine antibodies, were clearly stained after heating the sections. In the dot-blot analysis, the immunoblot sensitivity of detection was greatly enhanced by heating the protein-blotted membrane. These results indicate that other mechanisms of breaking formalin-induced cross-linkages may be present. We propose that one of the other mechanisms for heat-induced AR is that accessibility to the target epitopes of antigenic proteins is limited by natural steric barriers even in the fresh state caused by the antigenic protein itself.
authors.affiliation: Department of Pathology, Tokai University School of Medicine, 143-Shimokasuya, Isehara, Kanagawa, 259-1193, Japan.
authors.forename: Kochi
authors.initials: K
authors.lastname: Kakimoto
authors.forename: Susumu
authors.initials: S
authors.lastname: Takekoshi
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Miyajima
authors.forename: R Yoshiyuki
authors.initials: RY
authors.lastname: Osamura
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D005260:Female; D005557:Formaldehyde; D005629:Frozen Sections / Q000379:methods*; D006358:Hot Temperature; D007150:Immunohistochemistry / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011960:Receptors, Estrogen / Q000276:immunology; D016707:Tissue Fixation
chemical_list: D000906:Antibodies; D000941:Antigens; D011960:Receptors, Estrogen; D005557:Formaldehyde