Figure 4. Label-free real-time multi-parametric monitoring enables high content analysis.

(A) The contraction rate was analyzed for 48 hours (n  = 4 hCMC). The effect on the APD was determined for one hour after doxorubicin application and revealed a concentration dependent response with an EC₅₀ value of 17 µM (n  = 3 hCMC), (B) The impedance analysis revealed a concentration- and time-dependent decrease where IC₅₀ values could be determined for each time point (n  = 5 hCMC). (C) The microscopic analysis of the hCMC size (cross section area) showed an increase only for 100 µM after 24 hours and 48 hours (n  = 5). (D) After the experiment, the clusters were suitable for further molecular biological analysis. The immunocytochemical staining indicated typical stratification of contractile elements (arrows) in the control and 0.1 µM treated sample. These stratified elements were not observed in samples treated with 1 µM doxorubicin (bar  = 50 µm). For comparison with established in vivo cardiomyocyte damage markers, a c-troponin assay was performed on the culture media.