Objective

Human iPSC-derived cardiomyocyte (hiPSC-CM) is considered a novel promising tool for preclinical assessment of drug-induced cardiotoxicity, and various methods and platforms have been examined to evaluate cardiotoxic risks of drug candidates using hiPSC-CM. Among them, the use of fluorescent dyes to measure membrane action potential and Ca2+ transient is considered most suitable for high-throughput measurements, for example, in the case of toxicity screening. We established experimental protocols to measure membrane potential changes and Ca2+ transients in hiPSC-CM (iCell® Cardiomyocytes2, CDI) with a voltage-sensitive fluorescent dye (FluoVolt) and a calcium-sensitive fluorescent dye (Cal-520), respectively, on a kinetic plate reader, Hamamatsu FDSS/μCELL.