Figure 1. Immunohistological detection of 8-oxoguanine in the mouse retina. Immunostaining using an antibody raised against 8-oxoguanine (8-oxoG) was detected in liver of wild-type (A) and Ogg1-deficient mice (B), and in C57BL/6J mouse retina (C). A stronger signal was detected in liver of Ogg1-deficient mice as compared to wild-type mice. This confirmed the accumulation of the modified base. 8-oxoG was present in all retinal nuclear layers, in photoreceptor inner segments (IS), and in retinal pigment epithelium (RPE; arrow). The 8-oxoG labeling appears in brown. No signal was detected when the specific anti-8-oxoG antibody was omitted (D). Scale bar equals 50 µm in A and B, 25 μm in C, and 60 µm in D. Abbreviations: ganglion cell layer (GCL); inner nuclear layer (INL); outer nuclear layer (ONL).