On the specificity of 4-amino-5-methylamino-2',7'-difluorofluorescein as a probe for nitric oxide.
The specificity of 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) for nitric oxide was evaluated in in vitro systems. The probe was found fairly specific for nitric oxide. Potential sources of artifacts include the autoxidation of DAF-FM, potentiated by light, and its oxidation by sources of superoxide and peroxyl radicals, leading to fluorescence spectra indistinguishable from those of the nitric oxide adduct. Although DAF-FM reacts with peroxynitrite, this reaction seems to be of secondary importance under quasi-physiological conditions. On the other hand, a simultaneous presence of a nitric oxide source and a superoxide or hydrogen peroxide decreases or increases the fluorescence of DAF-FM, respectively, resulting in biased estimates of nitric oxide production.
Balcerczyk
Aneta
A
Department of Molecular Biophysics, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland. abal@biol.uni.lodz.pl
Soszynski
Mirosław
M
Bartosz
Grzegorz
G
D016477:Artifacts; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D005452:Fluoresceins / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D007202:Indicators and Reagents / Q000737:chemistry; D009569:Nitric Oxide / Q000032:analysis*; D010084:Oxidation-Reduction; D030421:Peroxynitrous Acid / Q000737:chemistry; D012680:Sensitivity and Specificity
C503301:4-amino-5-methylamino-2',7'-difluorofluorescein diacetate; D005452:Fluoresceins; D007202:Indicators and Reagents; D030421:Peroxynitrous Acid; D009569:Nitric Oxide