This antibody recognizes actin of skeletal, cardiac, and smooth muscle cells. It is not reactive with other mesenchymal cells except for myoepithelium. Actin can be resolved on the basis of its isoelectric points into three distinctive components: alpha, beta, and gamma in order of increasing isoelectric point. This mAb recognizes alpha and gamma isotypes of all muscle groups. Nonmuscle cells such as vascular endothelial cells and connective tissues are non-reactive. Also, neoplastic cells of nonmuscle-derived tissue such as carcinomas, melanomas, and lymphomas are negative. It stains tumors of smooth (leiomyomas and leiomyosarcomas) as well as skeletal muscle (rhabdomyomas and rhabdomyosarcomas).

Store the Muscle Actin antibody at 2-8°C (with azide) or aliquot and store at -20°C or colder (without azide).