【项目简介】
MCP-2 and CCL7 are two monocyte chemotactic proteins produced by human MG-63 osteosarcoma cells。Both MCP-2 and CCL7 are members of the C-C family of chemokines and share 62% and 71% amino acid sequence identity，respectively，with MCP-1。CCL7 also shares 58% amino acid identity with MCP-2.CCL7 cDNA encodes a 99 amino acid residue precursor protein from which the N-terminal 23 amino acid residues are cleaved to generate the 76 amino acid residue mature CCL7。Mature CCL7 contains a potential N-linked and several possible O-linked glycosylation sites.Similarly to other C-C chemokines，all three MCP proteins are monocyte chemoattractants。In addition, the three MCPs can chemoattract activated NK cells as well as CD4+ and CD8+ T lymphocytes。All three cytokines have also been shown to attract eosinophils and induce histamine secretion from basophils。

【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MCP-3抗体，当加入标准品和待测样本时，重组或天然的人MCP-3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MCP-3抗体可与被酶标板捕获的人MCP-3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MCP-3抗体+人MCP-3+生物素化抗人MCP-3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MCP-3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MCP-3的浓度。