5(6)-Carboxyfluorescein diacetate N-succinimidyl ester (CFSE, or CFDA SE, MBS258052) is a green fluorogenic reagent that binds to intracellular molecules. It is oft en used for cell proliferation and cytotoxicity studies.
CFSE diffuses into the cell and covalently binds to primary amino groups present on intracellular molecules. Intracellular esterases quickly cleave the acetate groups from the dye thus converting it to the fluorescent form. Any unbound reagent diff uses back out of the cell. Because CFSE forms a strong bond inside the cell, it is retained within the cell indefinitely and is inherited by daughter cells. It will not be incorporated into adjacent cells.
CFSE is supplied as a concentrated lyophilized powder at 0.05 mg. Reconstitute it with 200 ?L DMSO to yield a stock concentrate at 2500X (0.25 mg/mL). Dilute it 1:250 in PBS to form the 10X working solution, and then add it to cells at 1:10 (a final concentration of 0.1 ug/mL). Analyze with a fluorescence microscope or flow cytom-eter with a 488 nm blue argon excitation laser. CFSE exhibits green fluorescence in the FL1 region: excitation at 492 nm and emission at 520-540 nm (Figures 1-3).
As CFSE is detected in the green range, it is optimal for use in dual-staining studies with other fluorescent reagents, such as PI (
MBS258060), 7-AAD (
MBS258053), and SR-FLICA® with minimal spectral overlap. Use it with ICT’s SR-FLICA poly caspases inhibitor reagent to identify apoptotic cells in the analysis (Figure 3).
