Production and characterization of an estrogen receptor β subtype-specific mouse monoclonal antibody

An important step in differentiating the unique physiological roles of the α and β forms of estrogen receptor is to determine the precise expression pattern of each of these receptors. We report the generation and characterization of a murine IgG1 monoclonal antibody (MAb), ER15.64A that is ERβ subtype-specific and capable of recognizing full-length human ERβ as well as all of its known protein isoforms. ER15.64A, raised against a ERβ peptide (aa2-18)-keyhole limpet hemocyanine conjugate, reacted to the immunizing peptide and the full-length E. coli expressed ERβ in ELISA and BIAcore assays. It also immunostained nuclei of Sf9 insect cells that were infected with an ERβ-baculovirus. In Western analysis, ER15.64A recognized ERβ1 and ERβ2 proteins from a reticulocyte in vitro transcription/translation preparation. This antibody did not cross-react with recombinant ERα in ELISA, BIAcore, immunocytochemistry, or Western blot analysis. The specificity of ER15.64A should make this antibody a useful tool for mon...