Transmitochondrial embryonic stem (ES) cells can be differentiated into neurons and astrocytes. Parental ES cell lines (a and f, ES‐I; d, ES‐VI) and cybrids (b and g, CY3‐I SEVERE; c, CY2‐I MILD; e, CY2‐VI MILD) were differentiated and fixed on Day 13 for immunohistochemical analysis with the pan‐neuronal anti‐β‐tubulin III antibody (a–g, green) and astrocytic marker anti‐GFAP (F and G, red) as detailed in the Materials and methods. Nuclei are visualized by DAPI staining (blue). The sizing bar represents 20 µm.