Fig. 3. Colocalisation of plectin and AMPK in differentiated myotubes in a cross-striated pattern. Double immunofluorescence microscopy, using anti-plectin antiserum #46 and anti-AMPK 1 subunit antibodies, revealed distinct staining patterns in myoblasts (A-C). The staining patterns of AMPK (A) and plectin (B) were punctuated and filamentous, respectively, showing no colocalisation in distant cytoplasmic regions of myoblasts (C). By contrast, in differentiated myotubes (D-F) and on longitudinal sections of mouse skeletal muscle fibres (see Fig. 5), plectin and AMPK 1 showed extensive colocalisation, both in overlapping cross-striated patterns (F). Bars, 10 µm.