Skeletal muscle contains both differentiated myofibers and stem cells, known as satellite cells. The satellite cells, comprising around 1% of the total muscle nuclei, are situated between the plasma membrane of the multinucleated muscle cells and the basal lamina that surrounds each myofiber. In adult muscle, satellite cells are quiescent but proliferate in response to muscle injury, producing myoblasts that can either form new satellite cells or fuse with one another or pre-existing multinucleated muscle cells to help repair the muscle. They are responsible for postnatal muscle growth, hypertrophy and regeneration of skeletal muscle. When quiescent satellite cells are activated, they co-express the transcription factors Pax7 and myoD. HSkMSC from ScienCell Research Laboratories are isolated from human muscle of the pectoral girdle. HSkMSC are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HSkMSC are characterized by immunofluorescence with antibodies specific to Pax7 and/or actinin. HSkMSC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HSkMSC are guaranteed to further expand for 15 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Skeletal Muscle Cell Medium (SkMCM, Cat. #3501) for the culturing of HSkMSC in vitro.