【项目简介】
CD8, also known as Ly-2 or Leu-2, is a heterodimeric glycoprotein (alpha and beta subunits) that functions in conjunction with the T cell receptor in the recognition of MHC class I/peptide complexes. CD8 alpha is expressed on double positive (CD4+CD8+) thymocytes and mature CD8+cytolytic T cells (CTL), intraepithelial lymphocytes (IEL), some gamma-delta T cells, subsets of thymic and splenic dendritic cells (DC), and peritoneal mast cells. It can form disulfide linked homodimers or heterodimers with CD8 beta. Thymic CD8+ DC express primarily alpha beta heterodimers, while splenic CD8+ DC primarily express alpha alpha homodimers. CD8 alpha + DC can present viral antigenic peptides in complex with MHC I and prime CTL responses. The approximately 35 kDa mature mouse CD8 alpha consists of a 169 amino acid (aa) extracellular domain (ECD) with one Ig-like domain, a 21 aa transmembrane segment, and a 30 aa cytoplasmic domain. Within the ECD, mouse CD8 alpha shares 49% and 64% aa sequence identity with human and rat CD8 alpha, respectively.
 
【检验原理】
本试剂盒采用双抗体夹心ELISA法。酶标微孔板上预包被有抗小鼠CD8a抗体，当加入标准品和待测样本时，标准品和待测样本中的小鼠CD8a会和该抗体结合。洗板后，游离的其他成分被洗去，加入辣根过氧化物酶标记的的抗小鼠CD8a抗体可与被酶标板捕获的小鼠CD8a结合，形成“包被抗小鼠CD8a抗体+小鼠CD8a+抗小鼠CD8a抗体-HRP”免疫复合物。当加入TMB显色底物后，复合物上连接的HRP催化底物反应，生成蓝色产物，终止反应后变为黄色。在450nm处测定OD值，小鼠CD8a浓度与OD450值之间呈正比，可通过绘制标准曲线求出标本中小鼠CD8a的浓度。