Comparison of KOr fluorescence and Nestin protein distribution in cerebral cortices of E14.5 nestin/KOr mice. The genotypes of E14.5 embryos were determined by direct observation of their heads under the stereoscopic fluorescence microscope described in Figure 1. KOr-positive embryos were perfused with 4% paraformaldehyde (PFA) and the brains were removed. After additional overnight fixation in 4% PFA, they were cut into 14-μm sections with a Cryostat (Leica) and then immunohistochemically (IHC) processed with a mouse anti-Nestin primary antibody (Ab; BD Biosciences Rat-401; 1:100) and FITC-conjugated donkey anti-mouse secondary Ab (Jackson ImmunoResearch; 1:250). Fluorescent micrography was performed with an ApoTome fluorescence microscope (Zeiss) and the AxioVision software (Zeiss). Scale bar: 100 μm.