Figure 3. Representative fluorescence microscopy images of Myomerger-deficient C2C12 cells used to evaluate the efficiency of lipid mixing by analysis of redistribution of lipid probe (Dil) and content probe (CellTracker^TM Green).

Images of the cells after co-incubation of Dil-labeled cells with CellTracker^TM green-labeled cells in the differentiation medium. Nuclei are stained by Hoechst. Arrows indicate examples of several distinct phenotypes counted or not counted as mononucleated cells co-labeled with Dil and CellTracker^TM Green. A and B mark colabeled cells with stronger (A) and weaker (B) levels of Dil fluorescence. Cells like the ones marked as A and B were counted as co-labeled mononucleated cells. Cells labeled with only CellTracker^TM Green (C), or only Dil (D), or green cells with just one red point (E) or cells with more than one nucleus (F) were not counted as co-labeled mononucleated cells. Scale bar = 50 μm.