Actin, Smooth Muscle (SMA)

Antibody recognizes the α-smooth muscle isoform of actin. It shows no cross reaction with actin from fibroblasts (β and γ-cytoplasmic), striated muscle (α-sarcomeric), and myocardium (α-myocardial). Its epitope is composed of the acetyl group and the first 4 amino acids on the N-terminal end of the peptidic chain of a-smooth actin. This monoclonal antibody stains smooth muscle cells in vessel walls, gut wall, myometrium myoepithelial cells in breast and salivary glands. Antibody is reportedly useful for identifying tumors arising from smooth muscle and myoepithelial cells.