AICS11 were either co-cultured with IMR90-iCMs, or subjected to media change only as a control. Additional controls include non-differentiated iPS or GiWi-differentiated AICS11 or IMR90 cells. Total cells were harvested and immuno-stained for the cardiomyocyte markers (A) cTnT and (B) a-actinin, and analyzed by flow cytometry in conjunction with TOM20-GFP to distinguish AICS11 cells. As shown are representative flow plots for an experiment performed in triplicates. Calculation of cardiomyocyte differentiation efficiency for (C) cTnT and (D) a-actinin. Green bars indicate cells gated for GFP only, where % = Q2/(Q2+Q3)*100, while grey bars indicate total cells, where % = (Q1+Q2)/(Q1+Q2+Q3+Q4)*100. P-value for all pairwise comparison is ≤0.0001, except otherwise indicated, where ns is non-significant, and ** is <0.002.