Expression of neural progenitor markers in floating spheres. Fluorescence from the Sox1 reporter (A, Sox1, green) correlated with nuclear Sox1 expression detected with an antibody (B, Sox1, red). DAPI staining is shown (C) and co-staining by the two methods is shown in the merged image (D). Nestin expression (G, red) also increased in the Sox1 positive spheres (F, Sox1, green). The overlap in labeling is shown in the merged image (H). NeuroD was expressed (I, green) in spheres along with peripherin (J, red). DAPI is shown in blue (K) and the overlap in labeling is shown in the merged image (L). Scale bar is 50 microns.