Figure 5. Analysis of blebbistatin, a myosin-II inhibitor and excitation-contraction decoupler.

(A) Representative traces of the contractile profile from the brightfield method showed significant loss of contractility at higher concentrations. (D) At 1 and 10 nM the SVM accuracies were near 50%, suggesting minor to no changes in iPS-CMs. At 100 nM, the accuracy increased to 85.08 ± 1.49%. For 500 and 1000 nM, the respective SVM accuracies further increased and were both near 100% (n = 11). As expected with the GCaMP6 method, blebbistatin resulted in a false negative with no changes in (C) beating rate or (D) SR₉₀ at any of the tested concentrations (n = 11).