Background: Live cell fluorescence microscopy experiments often require visualization of the nucleus and the chromatin to determine the nuclear morphology or the localization of nuclear compartments. Methods: We compared five different DNA dyes, TOPRO-3, TOTO-3, propidium iodide, Hoechst 33258, and DRAQ5, to test their usefulness in live cell experiments with continuous imaging and photobleaching in widefield epifluorescence and confocal laser scanning microscopy. In addition, we compared the DNA stainings with fluorescent histones as an independent fluorescent label to mark chromatin.Results: From the dyes tested, only Hoechst and DRAQ5 could be used to stain DNA in living cells. However,