DAX-J2™ Ratio 580/460

DAX-J2™ Ratio 580/460 is a new nitric oxide (NO) sensor recently developed by AAT Bioquest. It is a cell permeable reagent that can measure free NO and nitric oxide synthase (NOS) activity in living cells in a ratiometric mode under physiological conditions. Once inside the cell the blocking groups on the DAX-J2 reagent are released to induce fluorescence ratio changes at wavelengths of 580 and 460 nm upon NO oxidation. The fluorescence intensities at 580 nm and 460 nm can be detected using the filter sets of Cy3®/TRITC and BD Horizon™ V450/Pacific Blue. These two filter sets are equipped with most of flow cytometers and fluorescence microscope. DAX-J2 Ratio 580/460 has distinct advantages for NO detection than the popular DAF-2 NO probe: 1). It does not require esterase activity for NO detection. DAF-2 requires intracellular esterases to cleave its acetate groups for detecting NO activity. This esterase dependence often complicates the NO detection since esterse activities are affected by cell health and many other factors. 2). DAX-J2 product exhibits pH-independent fluorescence while DAF-2 has its fluorescence highly affected by pH. 3). DAX-J2 Ratio 580/460 can be monitored in a ratiometric mode.