We used the Optopatch platform for all-optical electrophysiology (Hochbaum et al., 2014).  The Optopatch platform provides a robust assay to measure APs and CTs in hiPSC-CMs. 
Optopatch
We used the Optopatch platform for all-optical electrophysiology (Hochbaum et al., 2014).  The Optopatch platform provides a robust assay to measure APs and CTs in hiPSC-CMs. 
Optopatch platform
In a monolayer culture, a subset of cells expressed a genetically encoded, calcium and voltage reporter, CaViar (Hou, Kralj, Douglass, Engert, & Cohen, 2014), while others expressed a channelrhodopsin variant, CheRiff.  CaViar reported spontaneous and paced APs and CTs with high signal-to-noise ratio and low phototoxicity. 
CaViar
In a monolayer culture, a subset of cells expressed a genetically encoded, calcium and voltage reporter, CaViar (Hou, Kralj, Douglass, Engert, & Cohen, 2014), while others expressed a channelrhodopsin variant, CheRiff.  Optical pacing of CheRiff-expressing cells synchronized the syncytium. 
CheRiff