Phenotypic features of induced pluripotent stem cell-derived cardiomyocytes (iPS-CMs) and neonatal cardiomyocytes (N-CMs). (A,B) Sarcomeric alpha-actinin staining of iPS-CMs and N-CMs 5 days after plating taken at individually adjusted exposure intensity. Nuclei are DAPI stained, scale bar 100 μm. (C) Percentage of binucleated cells. (D) Expression of selected genes relevant for cardiomyocyte development determined by real-time PCR. *P < 0.05.