The biological effects of interleukin 2 （IL-2） are mediated by its binding to a multi-chain cellular receptor complex. The IL-2 receptor （IL-2 R） complex consists of three glycoprotein chains. The alpha chain （IL-2 R alpha/CD25） and beta chain （IL-2 R beta/CD122） act together with the gamma chain （IL-2 R gamma/CD132） to form a high affinity receptor that transduces the signal upon IL-2 binding. A soluble form of CD25/IL-2 R alpha is present in the serum in parallel with its increased cellular expression. There are reports of soluble IL-2 R beta as well. The biologic function of soluble CD25/IL-2 R alpha is unclear because，due to its low affinity，it is expected to be a poor inhibitor of IL-2. CD25/IL-2 R alpha is a precursor type I membrane protein with a signal peptide，an extracellular region，a transmembrane region，and a cytoplasmic domain. Studies suggest a correlation between the levels of CD25/IL-2 R alpha in serum with the onset of rejection in allograft recipients，with autoimmune disease activation in rheumatoid arthritis and systemic lupus erythematosis patients and with the course of some leukemias and lymphomas.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Human IL-2sRalpha BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Human IL-2sRalpha concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：15pg/mlRange：62.5-4000pg/mlSpecificity：Recognizes human L-2sRalpha.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti-h IL-2sRalpha monoclonal coating antibody is adsorbed onto microwells. IL-2sRalpha 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-2sRalpha antibody is added and binds to IL-2sRalpha captured by the first antibody. Following incubation unbound Biotinylated anti-h IL-2sRalpha antibody is removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti-h IL-2sRalpha antibody. Following incubation unbound Streptavidin-HRP is removed during a wash step. A colored product is formed in proportion to the amount of IL-2sRalpha 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-2sRalpha standard dilutions and IL-2sRalpha 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.
