Performing Human Skeletal Muscle Xenografts in Immunodeficient Mice

This protocol is significant because it can be used to create human skeletal muscle xenografts, which can be used to model muscle disease and to carry out preclinical therapeutic testing. This xenograft model allows researchers to study human muscle in vivo to better understand human muscle cell biology and to develop novel models for rare or acquired muscle diseases. After obtaining a human muscle biopsy, place the specimen in a 100-by-15-millimeter Petri dish containing muscle medium, and use a stereo microscope and surgical scissors to remove any remaining fascia or fatty tissue.

Dissect the muscle biopsy into approximately seven-by-three-by-three-millimeter pieces, taking care that the fibers are arranged longitudinally within the specimen. Next, transfer the Petri dish containing the dissected muscle on ice, and place synthetic, non-absorbable sutures in a 100-by-15-millimeter Petri dish of 70%ethanol. After confirming a lack of response to toe pinch in an eight-to 12-week-old, anesthetized NOD-Rag-gamma mouse, apply ointment to the immunodeficient animal's eyes, and use a trimmer to remove the hair overlying the tibialis anterior from the ankle to the knee.