Fig. 3

Expression of cardiomyocyte proteins. A, B Representative immunofluorescence and flow cytometry images showing the expression of cardiac transcription factors (Isl-1, Nkx2.5), cardiac structural protein (cardiac troponin T, cTnT), cardiac contractile protein (alpha-sarcomeric actin, α-SA) and left ventricular specific proteins (connexin-43, Tbx5 and IRX4) at on days 3, 5, 9 and 14 of differentiation. Secondary control was used as an experimental negative control in the absence of primary antibody to negate the non-specific binding of the secondary antibody and rule out false positive expression (Additional file 1: Figure S3). Nuclei were stained with DAPI. Initial green colour is due to the endogenous expression of GFP tagged pluripotent Nanog protein which gradually reduces and disappears with differentiation of cells. Positive staining is indicated by red colour. Scale bar = 50 µm. C, D Representative western blot images and quantitative scatter plot bar graphs showing the expression of ventricular specific proteins Cx43 (C) and MLC2V (D) at different time points