Muscle biopsies were obtained four weeks post-intramuscular injection of μDystro and μUtro. a, Representative H&E stain of muscle biopsies. Right panel for each dog shows higher magnification of the corresponding boxed region. Scale bar, 50 μm. b, Immunofluorescence staining of muscle biopsies against Utro_N and Utro_C. Scale bar, 50 μm. c, Immunofluorescence staining of muscle biopsies against CD3 and CD8; the bottom merged panel offers a validation of both antibodies. All experiments were repeated independently at least two times with similar results.