Stability of fluorescence-encoding plasmids. Segregational stability of plasmid pNT8 derivatives encoding the fluorescent proteins CFP (blue), GFP (green), YFP (yellow), DsRedExpress (red, solid line) or HcRed (red, broken line). L. monocytogenes harbouring the plasmids were propagated in BHI batch culture as described in the Methods section. Each point represents the average of data from three experiments. Error bars represent standard deviations.