预期应用
ELISA法定量测定人血清、血浆、细胞培养物上清或其它相关液体中CNP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CNP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CNP抗原、生物素化的抗人CNP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CNP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 CNP concentrations in cell culture supernates, serum, and plasma.
Introduction
CNP was originally isolated as a 22-amino-acid peptide from the porcine brain. The rat CNP precursor molecule, preproCNP, consists of 126 amino acid residues. It is a product of a gene that is distinct from the ANP or BNP genes and is highly conserved among species, with over 95 % homology among rat, human and porcine forms. The biologically active CNP consists of 22 amino acids. The N-terminal-extended form, CNP-53, is the major form in porcine brain. Immunoreactive CNP is found throughout the brain in the rat and humans, but outside the central nervous system little immunoreactive CNP is detected. However, in human breast tissue CNP immunostaining has been localized to vascular endothelial cells of small caliber arteries.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for CNP has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any CNP present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for CNP 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 CNP bound in the initial step. The color development is stopped and the intensity of the color is measured. | 
