Fig. 4. Semiquantitative analysis of MEF2C, Nkx-2.5 and GATA-4 protein expression 24 hours after treatment with 500 nM H₂O₂. Untreated and treated embryoid bodies were labelled with antibodies directed against the respective protein and immunofluorescence corrected for background fluorescence was quantified by confocal laser scanning microscopy and computer-assisted image analysis. The images show representative immunostainings. Bar, 200 µm. The bar chart represents pooled data from three experiments. ^*P<0.05, significantly different to the untreated control.