预期应用
ELISA法定量测定人血清、血浆、细胞培养物上清或细胞溶解物中NOS含量。
实验原理
本试剂盒应用双抗体夹心酶标免疫分析法测定标本中NOS水平。用纯化的抗体包被微孔板，制成固相抗体，往包被单抗的微孔中依次加入NOS抗原、生物素化的抗人NOS抗体、HRP标记的亲和素，经过彻底洗涤后用底物TMB显色。TMB在过氧化物酶的催化下转化成蓝色，并在酸的作用下转化成最终的黄色。颜色的深浅和样品中的NOS呈正相关。用酶标仪在450nm波长下测定吸光度（OD值），计算样品浓度。
Intended use
This immunoassay kit allows for the specific measurement of human NOS concentrations in cell serum, plasma and cell lysates.
Introduction
Nitric oxide (NO) is produced by a group of enzymes called nitric oxide synthases (NOS). These enzymes catalyze the production of NO and L-citrulline from L-arginine, O2, and NADPH-derived electrons. Mammalian systems contain three well-characterized isoforms of the enzyme: neuronal NOS (nNOS, also called NOS1), inducible NOS (iNOS or NOS2), and endothelial NOS (eNOS or NOS3). The names reflect characteristics of the activity or the original tissues in which the enzymes were first described, but it is now known that each of these isoforms is expressed in a variety of tissues and cell types. The cell types that express eNOS include vascular endothelial cells, cardiomyocytes and others. In blood vessels, NO produced by the eNOS in endothelial cells functions as a vasodilator thereby regulating blood flow and pressure. Mutant eNOS knockout mice have blood pressure that is 30% higher than wild-type littermates. Within cardiomyocytes, eNOS affects Ca2+ currents and contractility. Expression of eNOS is usually reported to be constitutive, though modest degrees of regulation occur in response to factors such as shear stress, exercise, chronic hypoxia, and heart failure.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for NOS has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any NOS present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for NOS is added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of NOS bound in the initial step. The color development is stopped and the intensity of the color is measured. |
