FIG. 4.

Immunostaining of cardiac organoids based on enriched cardiomyocytes cultivated at different stimulation modes. (A) Vimentin staining shows fibroblasts in red. Troponin-I staining shows cardiomyocytes in green. (B) Connexin-43 staining shows gap junctions in green (arrows). Cell nuclei are stained blue with 4′, 6-diamidino-2-phenylindole (DAPI). (C) Percentage of vimentin-positive cells. (D) Percentage of troponin-I–positive cells. Asterisks (*) denote statistically significant difference (p < 0.05; one-way ANOVA with post hoc Tukey's test). Color images available online at www.liebertonline.com/tea