Ultrastructural localization of actin in normal human skin.

Normal human skin was embedded in Lowicryl K4M. Actin microfilaments were localized by applying a postembedding immunogold technique using the monoclonal anti-actin antibody HHF35. Actin microfilaments are part of the cytoskeleton in muscle and nonmuscle cells. Together with myosin they produce contraction. The antibody labelled myofilaments in smooth muscle arrector pili cells, myoepithelial cells and pericytes. In sweat gland cells the microvilli system, a zone beneath the cytoplasma membrane corresponding to the adhesion belt region, and apocrine decapitation formations showed labelling.