预期应用
ELISA法定量测定人血清、血浆、细胞培养物上清或其它相关液体中sCD40L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sCD40L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sCD40L抗原、生物素化的抗人sCD40L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sCD40L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 human sCD40L concentrations in cell culture supernates, serum, and plasma.
Introduction
CD40 belongs to the TNF receptor superfamily. While the biological role of some of the ligand-receptor pairs in this family still remains obscure, CD40 has proven its importance.
A key role of CD40/CD40 ligand interactions in immune activation, particularly in T-cell dependent B cell responses is anticipated. This molecule as well as the other ligands of the family share the property of co-stimulation of T-cell proliferation and are all expressed by activated T-cells.
Because the ligand of CD40 (CD40L) is expressed on activated T helper cells, B cells may escape from apoptosis and are activated when the immune system interacts with foreign antigens, which are normally able to activate T-helper cells. Thus the CD40 - CD40L interaction plays a central role in the various phases of the B cell response to T dependent antigens.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for sCD40L has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any sCD40L present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for sCD40L 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 sCD40L bound in the initial step. The color development is stopped and the intensity of the color is measured.
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