IL-13 is a 17kD immunoregulatory cytokine that plays a key role in the pathogenesis of allergic asthma and atopy. It is secreted by Th1 and Th2 CD4+ T cells，NK cells，visceral smooth muscle cells，eosinophils，mast cells，and basophils. IL-13 circulates as a monomer with two internal disulfide bonds that contribute to a bundled four alpha-helix configuration. Mature human IL-13 shares 57%，59%，and 94%aa sequence identity with mouse，rat，and rhesus IL-13，respectively. Despite the low homology，it exhibits cross-species activity between human，mouse，and rat. IL-13 has diverse activities on numerous cell types. On macrophages，IL-13 suppresses the production of proinflammatory cytokines and other cytotoxic substances. On B cells，IL-13 induces immunoglobulin class switching to IgE，upregulates the expression of MHC class II，CD71，CD72，and CD23，and costimulates proliferation. IL-13 upregulates IL-6 while downregulating IL-1 and TNF-alpha production by fibroblasts and endothelial cells. IL-13 binds with low affinity to IL-13 R alpha 1，triggering IL-13 R alpha 1 association with IL-4 R alpha. This high affinity receptor complex also functions as the type 2 IL-4 receptor complex. Additionally，IL-13 binds with high affinity to IL-13 R alpha 2 which is expressed intracellularly，on the cell surface，and as a soluble molecule. IL-13 R alpha 2 regulates the bioavailability of both IL-13 and IL-4 and is overexpressed in glioma and several bronchial pathologies. Compared to wild type IL-13，the atopy-associated R110Q variant of IL-13 elicits increased responsiveness from eosinophils that express low levels of IL-13 R alpha 2.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Mouse IL-13 BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Mouse IL-13 concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：4pg/mlRange：7.8-500pg/mlSpecificity：Recognizes mouse IL-13.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti-m 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-m IL-13 antibody is added and binds to IL-13 captured by the first antibody. Following incubation unbound Biotinylated anti-m IL-13 antibody is removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti-m 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.
