Nitric Oxide/Nitrite Assay Kit - 1 kit

Nitric oxide (NO) is a potent endogenous vasodilator, and has a role inneurotransmission, inflammation, thrombosis, immunity, and control of cell growth and celldeath. Interest in measurement of NO increased exponentially with the discovery of theseversatile roles of NO in physiology as well as pathophysiology. Although NO can be measuredby diazotization of sulfanilic acid, electron paramagnetic resonance, met-hemoglobinconversion, and chemiluminescence reactions (FASEB J. &:349,1993), measurement of NO inbiological samples is difficult due to its low level and lability in the presence of oxygen. Nitriteis the major NO byproduct upon reaction with oxygen. Thus, the easiest method for NOmeasurement is the standard technique for measuring inorganic nitrite. This assay is basedon the observation that the adduct of nitroxides and sulfanilic acid interacts withN-(1-naphthyl)ethylenediamine, generating a product that is readily monitored byspectrophotometry (Anal. Biochem. 126:131,1982). Nitrite concentrations can be obtained bycomparison to a standard curve performed at the same time. The assay kit (sufficient for 500microplate assays) is stable for one year if stored refrigerated and shielded from light.