Fig. 3

8-Nitroguanine formation and p16 expression in biopsy specimens of patients with cervical dysplasia. a Immunoreactivity of 8-nitroguanine in a biopsy specimen of a patient with cervical intraepithelial neoplasia (CIN) grade 3. 8-Nitroguanine was formed in the nuclei of atypical epithelial cells of the CIN patient, whereas little or no DNA damage was observed in condyloma acuminatum patients. 8-Nitroguanine formation was examined as described in the caption to Fig. 2. b Comparison of 8-nitroguanine and p16 staining in patients with CIN grade 2 and condyloma acuminatum. Paraffin sections were first incubated with the primary antibodies (rabbit polyclonal anti-8-nitroguanine and mouse monoclonal anti-p16 antibodies) and then with the secondary antibodies (Alexa 594-labeled goat anti-rabbit IgG and Alexa 488-labeled goat anti-mouse IgG antibodies). 8-Nitroguanine (red) was colocalized with p16 (green) in the nuclei of atypical epithelial cells (yellow) in CIN, whereas, little or no 8-nitroguanine formation occurred in condyloma acuminatum [27]. Scale bar 50 μm