Spatial and Quantitative Immunofluorescence Analysis of Human Myogenic Cells in Mouse Skeletal Muscle Xenografts

Immunofluorescence analysis remains a cornerstone technique for evaluating the fate of transplanted human cells in xenograft models, as it provides essential spatial and phenotypic information unavailable through molecular quantification alone. This chapter outlines a standardized procedure for the preparation of human myogenic cells prior to intramuscular injection and then describes a comprehensive immunofluorescence-based method to identify, localize, and quantify human myogenic cells engrafted into regenerating skeletal muscle of immunodeficient mice. Using human-specific antibodies combined with extracellular matrix markers, this approach enables discrimination and classification of engrafted human cells as myonuclei, interstitial cells, or incorporated into the satellite cell niche. Quantitative strategies are presented to estimate total human cell numbers and assess longitudinal and transverse dispersion within host muscle tissue.