Novel drugs may have impact on Ca2+ transients that via Ca2+ dependent contractile proteins lead to arrhythmia or fibrosis of myocardium. In an attempt to test drugs under conditions that are close to physiologic conditions, 3D cultures of engineered heart tissue derived from iPSCs were monitored regarding their Ca2+ flux.
Using the Fluo-4 fluorescent Ca2+ indicator and a BMG LABTECH CLARIOstar®, Ca2+ transients were measured and overlapped with cardiac contractions. Addition of known modifiers of calcium transients changed the shape of the acquired calcium profiles as it was expected. This proves that the fast kinetic of calcium responses can be measured on the CLARIOstar and might be used to screen for calcium-related cardiotoxicity of drugs.