【项目简介】
Deltalike protein 1 (DLL1) is a 90 100 kDa type I transmembrane protein that belongs to the Delta/Serrate/Lag2 (DSL) family of Notch ligands. Mature human DLL1 consists of a 528 amino acid (aa) extracellular domain (ECD) with one DSL domain and eight EGFlike repeats, a 23 aa transmembrane segment, and a 155 aa cytoplasmic domain . Within the ECD, human DLL1 shares 91% aa sequence identity with mouse and rat DLL1. It shares 26%, 37%, and 54% aa sequence identity with DLL2, 3, and 4, respectively. A 60 kDa ECD fragment released by ADAM9, 12, or 17 mediated proteolysis, promotes the proliferation of hematopoietic progenitor cells . The residual membranebound portion of DLL1 can be cleaved by presenilindependent γsecretase, enabling the cytoplasmic domain to migrate to the nucleus . DLL1 localizes to adherens junctions on neuronal processes through its association with the scaffolding protein MAGI1 . DLL1 is widely expressed, and it plays an important role in embryonic somite formation, cochlear hair cell differentiation, plus B and T lymphocyte differentiation .The upregulation of DLL1 in arterial endothelial cells following injury or angiogenic stimulation is central to postnatal arteriogenesis . DLL1 is also overexpressed in cervical carcinoma and glioma and contributes to tumor progression . 

【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DLL1抗体，当加入标准品和待测样本时，标准品和待测样本中的人DLL1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人DLL1抗体可与被酶标板捕获的人DLL1结合，形成“包被抗人DLL1抗体+人DLL1+抗人DLL1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，人DLL1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DLL1的浓度。