Normal prelactating mammary gland in a mid-pregnant FVB female stained using the immunoperoxidase technique to identify smooth muscle actin. Note that the myoepithelial cells of the ducts and alveoli have heavy red-brown cytoplasmic stain. The antibody also identifies smooth muscle in blood vessels and some endothelial cells. (10x) The primary antibody is a monoclonal mouse antibody against human smooth muscle actin alpha. The MOM technique was used.
Compare the pattern in the 40x image with the IHC of CK14 and high and low molecular weight cytokeratin.
