There is another popular dye, CellTrace Violet, which uses violet excitation with blue emission. CellTrace Violet is fully compatible with GFP. CellTrace Violet and CellTrace CSFE are both amine-reactive succinimidyl ester compounds that covalently bind to proteins and give a bright homogenous fluorescence. When cells divide, the fluorescent label is distributed equally between daughter cells. As a result, each successive generation in a population of proliferating cells gives a reduction of fluorescence intensity, and generations can be identified.