Immunohistochemistry of ovarian and breast tissues. 4-A Immunohistochemistry of breast tumor tissue using 27.B1 (A, B, C) and 27.F7 (D, E, F) antibodies. Hyperplasia (A, D) and ductal carcinoma in situ (B, E) are negative, and invasive ductal carcinoma (C, F) is positive (Original magnification ×200). Black arrows indicate negative stained regions and red arrows indicate positive stained regions. 4-B Immunohistochemistry of ovarian tissue using 27.B1 (A, B, C) and 27.F7 (D, E, F) antibodies. Normal ovary: the epithelial monolayer is negative (A, D) (magnification ×400), borderline tumors (B, E) (magnification ×200) show different staining (27.B1 – positive, 27.F7 – negative). Epithelial serous carcinoma (C, F) is positive for both antibodies (magnification ×400). Black arrows indicate the negative staining and red arrows indicate the positive staining of the epithelium.