Immunocytochemical antigens detection in human breast carcinomas: a light and electron microscopy study using avidin biotin peroxidase and preembedding method.

An immunohistochemical study was carried out on a human breast carcinoma series with the aim to delineate the technical approach to distinguish the epithelial cells from stromal nonepithelial cells in the primary tumor and in cultured tumor cells. Frozen sections from 30 unfixed breast carcinomas were incubated with mouse monoclonal antiepithelial cell membrane antibodies and then with a biotinilizated antimouse antibody and the avidin biotin peroxidase complex (ABC). Thick (100 micron) sections from fresh, unfixed tissue were similarly treated prior to the araldite embedding procedure for EM study. In all cases the epithelial tumor cells were immunostained in contrast to nonepithelial stromal cells, particularly the fibroblasts. Because standard light microscopy fails to determine the real nature of the fusiforme cultured cells, it is suggested that these techniques represent a reliable method for mammary epithelial cell identification and may further be applied on cultured tissue.