title: Comparison of two microwave based antigen-retrieval solutions in unmasking epitopes in formalin-fixed tissue for immunostaining.
abstract: The present study compared two microwave based antigen-retrieval solutions in their ability to unmask antigenic determinants in formalin-fixed and paraffin-embedded tissues for Immunostaining. In this regard, two widely used antigen-retrieval solutions, namely 0.05 M glycine-HCl buffer, pH 3.6, containing 0.01% (w/v) (EDTA) and 0.1 M sodium citrate buffer, pH 6.0, were evaluated for (1) their effectiveness in unmasking a wide range of antigenic determinants (2) their ability to yield reproducible results (3) the lack of deleterious effects in any antibody antigen systems of interest. Both of these antigen-retrieval solutions resulted in greatly improved immunostaining following microwave-heating of dewaxed tissue sections for 2 x 5 min. Glycine-HCl buffer solution resulted in stronger immunostaining with antibodies to nuclear antigens [androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR), p53, proliferating cell nuclear antigen (PCNA), Ki-67 and MIB-1], cytoplasmic antigens (actin and factor-VIII) and cell-surface antigens [Cu-18, epithelial membrane antigen (EMA) and MT-1 (CD43)], whereas sodium citrate buffer yielded superior immunostaining with antibodies to vimentin, and some cell-surface antigens [common leukocyte antigen (CLA) (CD45) and UCHL-1 (CD45RO)]. The effect of unmasking the epitopes recognized by antibody to PCNA was equally effective with either of the antigen-retrieval solutions. Antibodies to pan-keratin, prostatic acid phosphatase (PAP), B lymphocyte antigen (BLA.36, CD20CY) and L26 (CD20) exhibited no enhancement in the intensity of staining with either of the antigen-retrieval solutions.
authors.affiliation: Department of Pathology, University of Southern California School of Medicine, Los Angeles 90033, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Imam
authors.forename: L
authors.initials: L
authors.lastname: Young
authors.forename: B
authors.initials: B
authors.lastname: Chaiwun
authors.forename: C R
authors.initials: CR
authors.lastname: Taylor
mesh_terms: D000941:Antigens / Q000032:analysis*; D000939:Epitopes; D005557:Formaldehyde; D006801:Humans; D007150:Immunohistochemistry; D008872:Microwaves; D013194:Staining and Labeling; D016707:Tissue Fixation
chemical_list: D000941:Antigens; D000939:Epitopes; D005557:Formaldehyde