Interleukin-13，or IL-13，is a pleiotropic cytokine that exhibits 30% sequence identity with IL-4 and shares many of the same biological activities. Like IL-4，IL-13 affects monocytes，macrophages and B cells by upregulating the expression of CD23 and MHC proteins，and downregulating the expression of CD14. Both IL-4 and IL-13 are secreted by activated T lymphocytes and are powerful regulators of inflammation. Both inhibit the secretion of proinflammatory cytokines and chemokines from activated monocytes and stimulate the expression of IgE on activated B cells. IL-13 contains five cysteine residues and multiple N-linked glycosylation sites and has been reported to inhibit the production of IL-2 in natural killer cells. IL-13 cDNA encodes a 131aa precursor with a 20aa signal peptide which is cleaved to generate a mature protein.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Human IL-13 BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Human IL-13 concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：30pg/mlRange：125-4000pg/mlSpecificity：Recognizes human IL-13.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti-h IL-13 monoclonal coating antibody is adsorbed onto microwells. IL-13 present in the sample or standard binds to antibodies adsorbed to the microwells. Following incubation unbound sample or standard are removed during a wash step. a Biotinylated anti-h IL-13 antibody is added and binds to IL-13 captured by the first antibody. Following incubation unbound Biotinylated anti-h IL-13 antibody is removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti-h IL-13 antibody. Following incubation unbound Streptavidin-HRP is removed during a wash step. A colored product is formed in proportion to the amount of IL-13 present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450nm. A standard curve is prepared from seven IL-13 standard dilutions and IL-13 sample concentration determined.Kit Components：Aluminium pouches with a Microwell Plate： 8x6Standard： 1xVialBiotinylated antibody： 1xVialStreptavidin-HRP： 1xVialAssay Buffer （25ml/Vial）： 1xVialWash Buffer Concentrate 20x （30ml/Vial）： 1xVialTMB Substrate Solution： 1x6mlStop Solution （12ml/Vial）： 1xVialPlate Covers- Adhesive strips： 2xstripsInstruction： 1xStorage and Stability：Store powder at 4°C liquid at -20°C. Store other components at 4°C. Stable for at least 6 months For maximum recovery of product，centrifuge the original vial after thawing and prior to removing the cap.
