ABSTRACT – Core B The goals of Core B is to provide 1) state of the art instrumentation and other resources to investigators studying skeletal muscle development and diseases, 2) assays for maturation of early stage muscle cells, and 3) testing and developing novel therapeutic interventions. The Core has instrumentation to assess contractile function at the protein, filament, cell, tissue and organ levels, and assays for measuring the developing properties of early stage muscle from animal and human sources such as inducible pluripotent stem cell derived muscle cells. The Core will train investigators individually and with workshop, and work with them to develop novel research assays for drug and small molecule testing, and investigating engineered cells and tissues and gene therapies that are being developed for clinical application and commercialization.