Single EDL Myofiber Isolation for Analyses of Quiescent and Activated Muscle Stem Cells

Adult satellite cells are quiescent, but are poised for activation in response to exercise, injury, or disease allowing adult muscle growth or repair. Once activated, satellite cells proliferate extensively to produce enough myogenic progenitors in order to regenerate the muscles. In order to self-renew, a subset of activated satellite cells can resist the myogenic differentiation and return to quiescence to replenish the satellite cell pool. These cellular processes that normally occur during skeletal muscle regeneration can be recapitulated ex vivo using isolated and cultured myofibers. Here, we describe a protocol to isolate single myofibers from the extensor digitorum longus muscle. Moreover, we detail experimental conditions for analyzing satellite cells in quiescence and progression through the myogenic lineage.