Fig. 3

Morphology and immunofluorescence identification of single cardiomyocytes and electrophysiological characterization of LQT7-iPSC-CMs. A The morphologies of single CMs in the different groups were similar, and the CMs could undergo contraction independently, as observed by microscopy. B Immunofluorescence identification of single CMs based on NKX2-5 (red, in the nucleus) and TNNT2 (green, myofilament). C The rhythm of spontaneous contraction of single cells in the three groups. D Typical patch clamp images of Kir2.1 potassium ion channel current changes in the CMs of each group are shown. E Meaning of the action potential-related electrophysiological values APA, APD₃₀, APD₅₀ and APD₉₀. F The action potential-related values of the CMs in each group were compared (Mutation n = 5, CRISPR n = 5, Control n = 5). G The potassium ion channel Kir2.1 is encoded by the KCNJ2 gene. The figure shows its current trace and I–V curve in a voltage-clamp pattern resulting from a holding potential of − 60 mV and test pulses ranging from − 60 to + 60 mV (Mutation n = 5, CRISPR n = 5, Control n = 5). Data are shown as mean ± SD.*p < 0.05; data were compared by two-sample t-test