A mouse satellite cell in its niche on an isolated myofibre. A myofibre isolated from the extensor digitorum longus muscle of an adult mouse. The associated quiescent satellite cell was coimmunostained for Pax7 and caveolin 1. Nuclei were counterstained with 4',6-diamidino-2-phenylindole (DAPI), revealing the location of the myonuclei in the myofibre. Scale bar = 20 μm.