Colorized scanning electron micrograph of a human embryonic stem cell (gold) growing on a layer of supporting cells (fibroblasts). Stem cells are derived from very early embryos and can either be grown to stay in their original state or triggered to form almost any type of human cell. The fibroblasts provide special factors that maintain the stem cells in their original state. The stem cell appears to be grasped by the underlying fibroblast.
B0006219 Human embryonic stem cell. Wellcome Images available under the following creative commons usage http://creativecommons.org/licenses/by-nc-nd/2.0/uk/