Preparation and identification of human breast epithelial cells in culture

The routine preparation of gram quantities of lobuloalveolar and ductal structures from human reduction mammaplasties by treatment with collagenase is described. When cultured on plastic or glass surfaces these structures give rise, initially, to epithelial sheets consisting of cells which retain many morphological characteristics of myoepithelial cells and do not stain with an antiserum which reacts with the surfaces of the lining epithelium of breast ducts and lobulo‐alveoli. Subsequently, cells which resemble the lining epithelial cells migrate from these structures and react strongly with the antiserum. Cell proliferation in these cultures is minimal. Explants of major ducts dissected from mastectomies produce vigorously proliferating epithelial sheets which contain morphologically similar cells not identifiable as either lining epithelium or myoepithelium, although nearly all the cells in direct contact with the medium react with the lining epitheliumspecific antiserum.