Expression of alkaline phosphatase by skeletal muscle fibers during skeletal muscle regeneration. Cross-sections from control TA (A-D), and after five (E-H), fifteen (I-L) and twenty eight (M-P) days after barium chloride injection were stained with anti-embryonic myosin antibodies (B, F, J, N) and detected with fluorescein-conjugated secondary antibodies. Merge of embryonic myosin staining (green) and laminin staining (red), as described in Figure 7, is shown (C, G, K, O). Merge of ALP staining using ELF-97 detection kit (blue) and laminin staining (red) from the same fields is shown (D, H, L, P). Phase contrast is shown at the top (A, E, I, M). Different fields showing ALP-negative/embryonic myosin-positive fibers five days after the injection are presented as inserts (E-H). Bar = 25 μm.