Fig. 1

Characterization of commercially available human pMB lines. A Experimental timeline for the 2D differentiation of the human primary myoblasts. B Representative 10X confocal images of the three commercially available human myoblasts immunostained for sarcomeric \(\alpha\)-actinin (SAA; magenta) and counterstained for DRAQ5 (grey) on day 9 of differentiation in 2D culture. Scale bar, 500 µm. C-E Bar graphs quantifying SAA coverage (C), average nuclear fusion index (D), and ratio of Pax7⁺ reserve cells amongst the mononuclear cells (E) in 2D culture on day 9 differentiation comparing the three cell lines. Graphs display mean ± s.e.m., one-way ANOVA with Tukey post-test. ** p < 0.01, *** p < 0.001, **** p < 0.0001, ns.—no significance. n = 3 wells from N = 1 experiment per cell line. F Schematic of the 24-well myotube template derivation workflow. G Representative confocal images of SAA (magenta) immunostaining in myotube templates at day 8 of differentiation that were generated using the 18M, 18F and 19F cell lines. Scale bar, 500 \(\upmu\)m. H Bar graph quantification of myotube template SAA coverage at day 8 of differentiation. Graphs display mean ± s.e.m., one-way ANOVA with Tukey post-test, ns. – no significance. n = 2 tissues from N = 1 experiment per cell line