ETHIDIUM BROMIDE
ethidium bromide: translation
A dye that intercalates into DNA and to some extent RNA. Intercalation into linear DNA is easier than into circular DNA and the addition of ethidium bromide to DNA prior to ultracentrifugation on a caesium chloride gradient is much used to separate nuclear and mitochondrial or plasmid DNA for analytical purposes. Because less intercalates into the circular DNA, the density remains higher.