Specific immunohistochemical detection of cardiac/fetal α-actin in human cardiomyocytes and regenerating skeletal muscle cells



We describe three murine monoclonal antibodies (mAbs) raised against a synthetic decapeptide representing the aminoterminal sequence of the cardiac/fetal isoform of sarcomeric α-actin. When used for immunoblotting or histological immunolocalization, these mAbs distinguish cardiac/fetal α-actin from skeletal muscle α-actin, and also from all other actin isoforms. We show, by immunofluorescence and immunoperoxidase microscopy of tissue sections, that cardiac/fetal α-actin can be localized not only in cardiomyocytes but also in skeletal muscles and their satellite cells during regeneration. These mAbs are potentially valuable in developmental biology, for the characterization of tissue and cultured myogenic cells, in patholoy, and for serodiagnosis.