Leptin, which is a product of ob gene, is a protein consisting of 167 amino acids and it is secreted from white adipose tissue. It is known that leptin acts on hypothalamus to decrease food intake and to reduce body weight, body fat, blood sugar and blood insulin in a healthy and an ob/ob mouse. Further, gene expression of neuropeptide Y (NPY) is suppressed by leptin. Recently, radioimmunoassay for leptin determination in human plasma has become available and leptin level in human patient group with obesity was found to increase in comparison with that of normal group. The level well correlate with body fat and these observations show clearly that leptin concentration in human plasma reflects the tissue fat weight. The measurement of plasma leptin may be an excellent index of obesity. Although rat leptin shows a high homology (96%) with mouse leptin, it is observed that substitution of several amino acid residues occurs at both end N- and C- terminal region between human and rat leptin. These findings have required urgently developing highly sensitive immunoassay system specific to rat leptin. Yanaihara Institute Inc. has developed the enzyme immunoassay (EIA) kit, which is a stable and convenient assay system for measuring rat leptin in its plasma, serum and culture supernatant.
This ELISA kit is used for quantitative determination of rat leptin in its plasma, serum and culture supernatant samples. The kit is characterized for sensitive quantification, high specificity and no influences with other components in samples and needlessness of sample pretreatment. Rat leptin standard is recombinant product.
This ELISA kit has high specificity to rat leptin and shows less than 0.02% - 0.04% cross reactivity to human leptin. And it has no cross reactivity with rat IL-1α, IL-1β, rat TNF-α, human TNF-α and other cytokines.
This ELISA kit for determination of rat leptin in plasma, serum and culture supernatant samples is based on a sandwich enzyme immunoassay. The 96-wells plate is coated with anti rat leptin monoclonal antibody. Rat leptin standard or samples and HRP-labeled anti rat leptin polyclonal antibody are added to the wells for one step sandwich immunoreaction. During this immunoreaction, monoclonal antibody-antigen-HRP labeled antibody complex are formed on the surface of the wells. After incubation and plate washing, HRP enzyme activity is determined by o-Phenylenediamine dihydrochloride (OPD) and the concentration of rat leptin is calculated.