Figure 1.

Light microscopic images of the mouse testis showing the effects of different pretreatments for 5-bromo-2’-deoxyuridine (BrdU) immunohistochemistry as detected using the enzyme method. Paraffin sections of the testis were left untreated (A) or subjected to a pretreatment with HCl (B) or heat-induced antigen retrieval (HIAR; C, D) and then immunostained with the mouse monoclonal anti-BrdU antibody (A–C) or normal mouse IgG (D). In (B) and (C), BrdU was localized in the nuclei (arrowheads) of the seminiferous tubules. In (A) and (D), no nuclear staining was observed. Scale, 100 μm.