Figure 4. Immunocytochemical analysis of sphere colonies from the peripheral stroma on day 7. Bright-field images and immunostaining of spheres are shown. The spheres were stained for vimentin (a mesenchymal cell marker), \alpha-smooth muscle actin (α-SMA, a mesenchymal cell marker), cytokeratin 3 (a differentiated epithelial cell marker), nestin (a neural stem cell marker), microtubule-associated protein 2 (MAP2, a differentiated neural cell marker), neuron-specific enolase (NSE, a differentiated neural cell marker, and CD34 (a stem cell marker). Each colony is also labeled by BrdU. As a negative control, IgG was used instead of the primary antibody. Scale bar=100 μm.