Morphology of cultured Sertoli cells (SCs). (A) Primary SCs at 4 hours after plating (magnification 100×). The white arrow indicates a SC, and the black arrow indicates a germ cell. (B) Passage 2 SCs with residual germ cells removed (magnification 100×). (C) SC monolayer on day 3 after culture (magnification 100×). (D) Passage 2 SCs stained with hematoxylin (magnification 200×). The black arrow indicates a SC.