【项目简介】
MIP-3 beta，also known as ELC (EBI1-Ligand Chemokine)，is one of many novel beta chemokines identified through bioinformatics。MIP-3 beta cDNA encodes a 98 amino acid (aa) residue precursor protein with a predicted 21 aa residue signal peptide that is cleaved to form the 77 aa residue mature secreted protein。MIP-3 beta is distantly related to other beta chemokines (20-30% aa sequence identity) and the gene for MIP-3 beta  has been mapped to chromosome 9p13 rather than chromosome 17 where the genes for many human beta chemokines are clustered。 MIP-3 beta has been shown to be constitutively expressed in various lymphoid tissues (including thymus，lymph nodes，appendix and spleen)。MIP-3 beta has also been shown to be a unique functional ligand for CCR-7 (previously referred to as the Epstein-Barr virus-induced gene 1 (EBI1) orphan receptor)， a chemokine receptor that is expressed in various lymphoid tissues and activated B and T lymphocytes. EBI1 is strongly up-regulated in B cells infected with Epstein-Barr virus and T cells infected with herpesvirus 6 or 7。

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