Figure 1.

Local and global spontaneous myotube alignment. C2C12 myoblasts were cultured on TC polystyrene and stained for F-actin after 9 days of differentiation. (a) Sample images (of n = 4) show that in conventional cell culture the degree of cellular alignment decreases with increasing field of view (FOV). Scale-bars: (left to right) 100 µm, 250 µm, 1 mm (b) Myotube alignment was quantified from F-actin images using the ImageJ Plug-in, OrientationJ, and given as an alignment score (0–1) for multiple FOVs ranging from 0.125 mm² to 16 mm². Areas shaded in dark grey indicate values below theoretical point of random alignment (0.11) for the analysis method (c) Large FOV images (16 mm², scale bars = 1 mm) of C2C12 myotubes on various substrates at day 9 of differentiation. Left to right: TC polystyrene, 10% w/v gelatin—10 U/mL Transglutaminase (TG), 5% w/v gelatin—10 U/mL TG and 2.5% w/v gelatin—10 U/mL TG. (d) Alignment score as a function of FOV for C2C12 myotubes developed on various substrates. Left to right: TC polystyrene, 10% w/v gelatin—10 U/mL TG, 5% w/v gelatin—10 U/mL TG and 2.5% w/v gelatin—10 U/mL TG. Points indicate mean ± s.e.m. (n = 4). Evaluation performed on day 9 after initiation of differentiation.