5(6)-Carboxy-2’,7’-dichlorofluorescein diacetate is an oxidant-sensitive and cell-permeable fluorescent probe.1Base hydrolysis of the ester bonds by intracellular esterases releases the acetate groups and the resulting compound, 5(6)-carboxy-2’,7’,-dichlorofluorescein, is oxidized by reactive oxygen species (ROS) and nitric oxide (NO) and displays excitation/emission maxima of 504 and 530 nm, respectively, which can be quantified as a measure of oxidant production. 1.Hempel, S.L., Buettner, G.R., O’Malley, Y.Q., et al.Dihydrofluorescein diacetate is superior for detecting intracellular oxidants: Comparison with 2’,7’-dichlorodihydrofluorescein diacetate, 5(and 6)-carboxy-2’,7’-dichlorodihydrofluorescein diacetate, and dihydrorhodamine 123Free Radic. Biol. Med.27(1-2)146-159(1999)

2',7'-Dichlorofluorescein diacetate (Diacetyldichlorofluorescein), a cell-permeable fluorogenic probe, is useful for the detection of nitric oxide (NO) and reactive oxygen species (ROS) and for the determination of the degree of overall oxidative stress.