Neurone development, embryoid body

An 8 day old 3D cluster of cells (embryoid body) formed from mouse embryonic stem cells. The cells were grown in factors to encourage development of the nervous system (neural differentiation). Mature neurones (beta-tubulin, green) are seen extending across the surface of the embryoid body which is made up of immature neural cells (nestin, red). Imaged by fluorescence immunocytochemistry. Image width is 2.28 mm.