Fig. 5. Histone H1 colocalizes with perlecan in regenerating skeletal muscle. Hamster tibialis anterior muscle was induced to regenerate for four (d4) or five days (d5) after a barium chloride injection. (A) Serial cryosections were stained with hematoxylin/eosin to visualize morphological progression. (B) Similar sections were double stained with monoclonal antibodies against histone H1 (H1) or embryonic myosin (em) together with a polyclonal anti-perlecan (per) antibodies. TRITC-conjugated anti-mouse IgG and FITC-conjugated anti-rabbit IgG were used as secondary antibodies. Nuclei in regeneration foci were visualized by Hoechst 33258 nuclear staining (Ho). As a control, cryosections of non-injected hamster muscle (ctrl) were similarly analyzed. Inserts correspond to the regions marked with a dotted square in the respective sections. Arrows indicate the colocalization of anti-histone H1 and anti-perlecan antibodies in the ECM. Bar, 25 µm.