NucPE1

NucPE1 (Nuc-H2O2 Probe) is a nuclear-localized fluorescent hydrogen peroxide that is specifically localized to cellular nuclei without appended targeting moieties. In Vitro: NucPE1 features two major visible region absorptions (λ_abs=468 nm, ε=27,300 M^-1cm^-1; λ_abs=490 nm, ε=26,000 M^-1cm^-1) and a weak emission (λ_em=530 nm, Φ=0.117). Reaction of NucPE1 with H₂O₂ triggers a fluorescence increase upon its conversion to fluorophore NucPE1, which possesses one major absorption band at 505 nm (ε=19,100 M^-1cm^-1) with enhanced emission (λ_em=530 nm, Φ=0.626). NucPE1 selectively accumulates in the nuclei of a variety of mammalian cell lines as well as in whole model organisms like C. clegans, where it can respond to subcellular changes in H₂O₂ fluxes^[1]. In Vivo: NucPE1 maintains the ability to selectively target nuclei in vivo. NucPE1 imaging reveals a reduction in nuclear H₂O₂ levels in worms overexpressing sir-2.1 compared to wildtype congeners, supporting a link between this longevity-promoting sirtuin protein and enhanced regulation of nuclear ROS pools^[1].