The study aimed to comprehensively characterize human myoblastic cell line RCMH using using electron microscopic and proteomic approaches. Myoblastic cell lines can be useful to investigate the complex biochemical changes occuring under different conditions that reflect the physiological and pathophysiological mechanisms of muscle. So far, there are no suitable in vitro models of human muscle origin to study a variety of muscle related processes including responses to mechanical stress, EC-coupling and (ER-associated) myopathic disorders. Therefore, we characterized the human immortal myoblastic cell line RCMH and the results suggest RCMH as a suitable in vitro model for investigating human muscle related processes and disorders.