预期应用
ELISA法定量测定鸭血清、血浆或其它相关液体中白介素2(IL-2)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IL-2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IL-2抗原、生物素化的抗鸭IL-2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IL-2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 Interleukin 2 (IL-2) concentrations in cell culture supernates, serum and plasma.
Introduction
Interleukin 2 (IL-2) is a pleiotropic cytokine produced primarily by mitogen- or antigen-activated T lymphocytes. It plays a key role in promoting the clonal expansion of antigen-specific T cells. In addition, IL-2 has also been shown to mediate multiple immune responses on a variety of cell types. IL-2 stimulates the proliferation of thymocytes; stimulates the proliferation and differentiation of activated B cells; promotes the growth, differentiation and cytocidal activity of monocytes; induces the growth of natural killer cells and stimulates cytokine production by these cells as well as the cytolytic activity of these cells; enhances the production of lymphocyte-activated killer (LAK) cells; and induces the proliferation and differentiation of oligodendrocytes.
The sequence of duck IL-2 cDNA predicts a 153 amino acid (aa) residue precursor glycoprotein containing a 20 aa residue signal peptide that is cleaved to form the mature protein. At the amino acid sequence level, mouse IL-2 is approximately 60% identical to duck IL-2. Whereas duck IL-2 is active on mouse cells, mouse IL-2 is species-specific and is inactive on duck cells. The gene for IL-2 has been mapped to duck chromosome 4q.
The biological effects of IL-2 are mediated by specific cell surface receptor complexes. The functional high-affinity receptor for IL-2 is composed of three distinct polypeptide chains, the IL-2 receptor α, β, and γ subunits. The intermediate-affinity IL-2 receptor complex, which lacks the αsubunit but contains both the βand γsubunits, is also capable of transducing the IL-2 signal . The βand γsubunits of the IL-2 receptor have been shown to be components of the high-affinity receptor complex for IL-15 , a novel cytokine that shares many biological properties with, but lacks amino acid sequence homology to, IL-2. In addition, the γsubunit is a component in the IL-4, IL-7 and IL-9 receptor complexes.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-2 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any IL-2 present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for IL-2 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 IL-2 bound in the initial step. The color development is stopped and the intensity of the color is measured.
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