4,5-Diaminofluorescein - DAF-2

DAF-2 (4,5-Diaminofluorescein) shows higher photostability than the classical fluorescein derivative DAF. Applications: DAF-2 is highly sensitive reagent for NO detection and determination of nitric oxide synthase activity. DAF-2, however, remains essentially nonfluorescent until it reacts with the nitrosonium cation (produced by spontaneous oxidation of nitric oxide) to form a fluorescent heterocycle, which becomes trapped in the cell's cytoplasm. This sensitive fluorescent probe has been used to identify individual nitric oxideproducing neurons in brain slices, in mitochondria and in living plant cells.

In the cell, the product reacts rapidly with NO in the presence of O2 to form the highly fluorescent compound triazolofluorescein (DAF-2T (Cat-No. S5442 >)).

References: (1) M. Kirsch et al.; J. Pineal Res. 40(1), 10 (2006), (2) V.M. Dirsch et al.; Biol. Proc. Online 5(1), 136 (2003), (3) N. Nagata et al.; J. Biochem. 125(4), 658 (1999), (4) H. Kojima et al.; Chem. Pharm. Bull. 46, 373 (1998), (5) H. Kojima et al.; Anal. Chem. 70, 2446 (1998)