Human NOS2/iNOS(Nitric Oxide Synthase 2, Inducible) ELISA Kit (E-EL-H0753)

This ELISA kit uses the Sandwich-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with an antibody specific to Human NOS2/iNOS. Standards or samples are added to the micro ELISA plate wells and combined with the specific antibody. Then a biotinylated detection antibody specific for Human NOS2/iNOS and Avidin-Horseradish Peroxidase (HRP) conjugate are added successively to each micro plate well and incubated. Free components are washed away. The substrate solution is added to each well. Only those wells that contain Human NOS2/iNOS, biotinylated detection antibody and Avidin-HRP conjugate will appear blue in color. The enzyme-substrate reaction is terminated by the addition of stop solution and the color turns yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450 nm ± 2 nm. The OD value is proportional to the concentration of Human NOS2/iNOS. You can calculate the concentration of Human NOS2/iNOS in the samples by comparing the OD of the samples to the standard curve.

Nitric oxide synthase 2 (NOS2), also called inducible nitric oxide synthase (iNOS), is a calmodulin-dependent enzyme that converts L-arginine to L-citrulline and nitric oxide (NO). It is barely expressed in resting cells but is strongly induced by lipopolysaccharide and by inflammatory cytokines such as interferon-gamma and tumor necrosis factor alpha, with transcription controlled mainly by NF-kappaB. Inducible expression appears in macrophages, vascular smooth-muscle cells, cardiomyocytes and many other cell types, and catalysis requires cofactors including NADPH, FAD, FMN and tetrahydrobiopterin. Once induced, NOS2 generates large amounts of nitric oxide continuously, providing the cytotoxic basis for the antitumor and antimicrobial activity of macrophages. Nitric oxide also modifies proteins through S-nitrosylation of cysteine residues. When induction is excessive, the resulting nitrosative and oxidative stress damages host tissue, illustrating the dual signaling and cytotoxic nature of the product. Dysregulated NOS2 contributes to septic shock, chronic inflammation, autoimmune disease and cancer, and the enzyme is a central effector of innate immunity as well as an important target in inflammation research. Quantitative determination of NOS2 supports investigation of anti-infective and anti-inflammatory mechanisms and of the irreplaceable role this enzyme plays in macrophage-mediated killing of microorganisms.