Figure 3.

Detection of EMA. Serial sections of formalin-fixed paraffin-embedded breast tissue were prepared for immunohistochemistry as described in the text and incubated with monoclonal antibody to EMA diluted 1:1600 (A and E); 1:6400 (B and F); 1:25,600 (C and G); or antibody diluent alone (D and H). After development with either standard immunohistochemistry techniques (A–D) or immuno-RCA (E–H), sections were screened for alkaline phosphatase activity (blue stain) and counterstained with Nuclear Fast Red. All panels, representing the same region of the breast tissue, were photographed at an original magnification of ×20. Epithelial cells of the breast ducts and lobules were uniformly positive for EMA. IHC, immunohistochemistry.