Figure 6. BrdU labeling in mature RPE cells. A and B: Shows a binucleated labeled cell with BrdU on red channel and Otx green channel. C shows two adjacent mono-nucleated cells that are labeled with BrdU. Scale bar equals 20 µm. D shows an outline drawing on which the location of RPE cells labeled with Ki67 and BrdU are marked. The diagram shows the distribution of positive BrdU-labeled binucleated (black dots) and mononucleated (black circle) cells. Only a small number of the BrdU-labeled cells were more centrally located than those labeled for Ki67. The mononucleated cells were almost always found in pairs of close proximity. The red dots represent the number and distribution of Ki67 positive RPE cells. While these largely overlap with the BrdU labeled population of RPE cells, they tend to occupy a slightly more peripheral location. The scale bar represents 2.5 mm.