本试剂盒应用双抗体夹心酶标免疫分析法测定标本中补体C4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补体C4、生物素化的抗补体C4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补体C4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 complement C4 concentrations in serum and plasma.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal
antibody specific for complement C4 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any complement C4 present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for complement C4 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 complement C4 bound in the initial step. The color development is stopped and the intensity of the color is measured.
