Background: Reactive nitrogen intermediates (RNI) and reactive oxygen intermediates (ROI) work together to damage cells and have been implicated in the pathogenesis of several disease states. RNI are a family of molecules derived from nitric oxide (NO) and superoxide anion (O2-), produced via nitric oxide synthase (NOS) and NADPH oxidase, respectively. Nitric oxide is an established mediator in vascular diseases, diabetes, renal ischemia, atherosclerosis, inflammatory diseases, and cancer. However, because of its extremely short half life, direct quantitation of NO production remains challenging and unsuitable for most detection systems. Therefore, the common method for measurement of total NO has become the sum of its final oxidized products, nitrite (NO2-) and nitrate (NO3-) (Figure 1). The OxiSelect™ Nitric Oxide (Nitrite/Nitrate) Assay Kit is a simple, fluorometric assay that quantitatively measures NO in various samples by NO2-/NO3- determination. First, the nitrate (NO3-) in the sample is converted to nitrite (NO2-) by nitrate reductase enzyme (Figure 2). Next, total nitrite is detected with the fluorescent probe DAN (2,3-diaminonaphthalene). Each kit provides sufficient reagents to perform up to 100 assays using a 96-well microtiter plate format, including blanks, standards and unknown samples. The kit is suitable for serum, plasma, urine, saliva, lysates, and media (see Preparation of Samples) with detection sensitivity limit of ~ 500 nM (in 50 uL sample volume).

1. Moncada, S. (1992) Acta Physiol. Scand. 145, 201-227.
2. Nathan, C. (1992) FASEB J. 6, 3051-3064.
3. Schreck, R. and Baeuerle, P.A. (1991) Trends Cell Biol. 1, 39-42.
4. Ignarro, L.J. (1990) Pharmacol. Toxicol. 67, 1-7.
5. Green, L.C., et al. (1982) Anal. Biochem. 126, 131-138.

Small volumes of OxiSelect In Vitro Nitric Oxide (Nitrite / Nitrate) assay kit vial(s) may occasionally become entrapped in the seal of the product vial during shipment and storage. If necessary, briefly centrifuge the vial on a tabletop centrifuge to dislodge any liquid in the container`s cap. Certain products may require to ship with dry ice and additional dry ice fee may apply.

MBS168898 is an assay kit targeting OxiSelect In Vitro Nitric Oxide (Nitrite / Nitrate). Also known as OxiSelect In Vitro Nitric Oxide (Nitrite / Nitrate) Assay Kit (Fluorometric).