Antigen retrieval for bcl‐2 protein in formalin‐fixed, paraffin‐embedded sections

A commercial monoclonal antibody to bcl-2 protein (bcl-2, 124) is useful in immunohistochemical detection of this 25 kDa oncogene product in frozen sections. In order to overcome the difficulty in identifying bcl-2 protein in formalin-fixed, paraffin-embedded sections, its antigenicity was retrieved by a variety of pretreatments. The heating pretreatment by hydrated autoclaving was the best method for retrieving the antigenicity, and deionized water was the most adequate solution for soaking sections. This antigen retrieval sequence was helpful to examine the localization of bcl-2 protein in archival sections of normal lymphoid and nonlymphoid tissues and follicular lymphomas.