L6 cells fuse in culture to form multinucleated myotubes and striated fibers. The extent of cell fusion declines with passage and the cells should be frozen at low passage and periodically recloned with selection for fusion competent cells; the myoblastic component of this line will be depleted rapidly if the cells are allowed to become confluent; tested and found negative for ectromelia virus (mousepox)Tumorigenecity:Isoenzyme:Histopathology:normalSubculture:Split ratio:Media change:Reverse transcritase:Productionmyosin