Single, mid-level plane of live hiPSC-derived cardiomyocytes expressing mEGFP-tagged alpha-actinin-2 protein. Inset shows 2.5x enlargement of boxed region to show myofilament detail. Twelve days after the onset of differentiation, cells were plated on PEI and laminin coated glass and imaged in 3D on a spinning-disk confocal microscope 7 days later (19 days total after the onset of differentiation). Scale bar, 20μm