Diaminofluorescein –2 Diacetate (DAF-2DA) is a
non-fluorescent cell permeable reagent that can measure free
Nitric Oxide (NO) and nitric oxide synthase (NOS) activity
in living cells under physiological conditions. Once inside
the cell the diacetate groups on the DFA-2DA reagent
arehydrolyzed by cytosolic esterases thus releasing FAD-2
and sequestering the reagent inside the cell. Production of
nitric oxide converts the non-fluorescent dye, DAF-2, to its
fluorescent triaole derivative, DAF-2T .
DAF-2T can be observed by: excitation 488nm and measuring
emission at 515nm.
DAF-2DA can be used to detect NOS activity
in cell culture or tissue sections. This reagent is not species
specific and can also be used to detect NOS activity in plant
Formulation: DAF-2DA is dissolved in DMSO at approx 5mM.
kits are available:
0.125 mg per vial at 2.22 mg/mL.
0.25 mg per vial at 2.22 mg/mL.
Fig 1. DAF-2DA, the non-fluorescent probe, enters
the cells where cytosolic esterases hydrolysis the
diacetate groups, releasing the non-fluorescent
DAF-2 dye. DAF-2 then reacts with NO and O2 to
produce DAF-2T, its triazole fluorescent derivative.
Fig 2. Phase Contrast and fluorescent microscopic
images of rat aorta-derived vascular smooth muscular
cells loaded with DAF-2DA .