Triple label immunocytochemistry in the dorsal anterior nasal epithelium of a 4 day post-BrdU injection mouse (c). SCCs, identified with anti-α-gustducin, are shown in red. Nuclei which have incorporated BrdU are shown in green and all nuclei, stained with propidium iodide, are shown in blue. Scale bar = 50 μm. Note the double labeled SCC in the upper left (arrow). At the two day time point (a) no colocalization was seen. The first double labeled SCCs were observed at three days post-BrdU injection (b) and double labeled cells were still evident at 12 days post-BrdU (e). Scale bars in a, b, d, and e = 20 μm.