【项目简介】
Human CD276 also known as B7-H3，was originally identified as a 316 amino acid (aa) type I membrane precursor protein with a putative 28 aa signal peptide，a 217 aa extracellular region containing one V-like and one C-like Ig domain，a transmembrane region，and a 45 aa cytoplasmic domain。Subsequently，a second dominantly expressed form of human B7-H3，containing a splice variation that duplicates the V-like and C-like Ig domains, was found。The 534 aa splice variant of B7-H3 has been referred to as B7-H3b，4Ig-B7-H3，and B7-H3VCVC。RTPCR transcripts for both B7-H3 and 4Ig-B7-H3 have been found in all tissues except peripheral blood leukocytes。Southern blot analysis indicates that the 4Ig-B7-H3 isoform of B7-H3 is the predominate isoform expressed in human tissues。
 
【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人CD276抗体，当加入标准品和待测样本时，重组或天然的人CD276会和该抗体结合。洗板后，游离的其他成分被洗去，加入生物素化的抗人CD276抗体可与被酶标板捕获的人CD276结合。再次洗板后，游离的其他成分被洗去，加入辣根过氧化物酶标记的链霉亲和素，生物素和链霉亲和素特异性结合，形成“包被抗人CD276抗体+人CD276+生物素化抗人CD276抗体+链霉亲和素-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，人CD276浓度与OD450值之间呈正比，可通过绘制标准曲线求出标本中人CD276的浓度。