EGF是表皮生长因子(Epidermal Growth Factor)是一种人体自有的广泛存在于皮肤细胞内的小分子蛋白，是由53个氨基酸组成的活性多肽，其分子量为6216道尔顿，分子结构中有三对二硫键，决定着它的生物活性。
本试剂盒应用双抗体夹心酶标免疫分析法测定标本中EGF水平。用纯化的抗体包被微孔板，制成固相抗体，往包被单抗的微孔中依次加入EGF抗原、生物素化的抗兔EGF抗体、HRP标记的亲和素，经过彻底洗涤后用底物TMB显色。TMB在过氧化物酶的催化下转化成蓝色，并在酸的作用下转化成最终的黄色。颜色的深浅和样品中的EGF呈正相关。用酶标仪在450nm波长下测定吸光度（OD值），计算样品浓度。
Intended use
This immunoassay kit allows for the specific measurement of rabbit EGF concentrations in plasma and cell culture supernates.
Introduction
Epidermal growth factor (EGF) was discovered in crude preparations of nerve growth factor prepared from mouse submaxillary glands as an activity that induced early eyelid opening, incisor eruption, hair growth inhibition, and stunting of growth when injected into newborn mice.
EGF is a member of a family of growth factors that bind to the same 170 kDa receptor,including TGF-a, vaccinia growth factor and amphiregulin. EGF is initially synthesized as a large (130 kDa) precursor molecule in which the mature, soluble EGF sequence (6 kDa) is located. The precursor, which functions as a source for soluble EGF, may also have a role in mediation of intercellular communication between cells displaying pro-EGF on their surfaces and cells with EGF receptors. This “juxtacrine” activity is also shown by a number of other unrelated factors.
Cells known to express EGF include platelets, cerebral neurons, astrocytes, cerebellar Purkinje cells, cells of the Brunner (duodenum) and submandibular glands, non-pigmented ciliary epithelium, and cells of the anterior pituitary.
EGF signals via binding to the EGF receptor (EGFR) (also known as HER1 or ErbB1), a transmembrane receptor tyrosine kinase of the ErbB family. Monomeric mature EGF has been shown to bind the extracellular domain of ErbB1 and induce the homo-dimerization with another ErbB1, or heterodimerization with ErbB2. ErbB2 is an ErbB family protein that does not bind any ligands directly but is a preferred heterodimerization partner with ErbB1, 3, or 4. At high concentrations, EGF can also signal via the ErbB3:ErbB2 heterodimer. Cross-talk between the EGF/EGF receptor pathway with the HGF receptor pathway or the PDGF receptor pathway has been reported.
A large number of diverse biological effects have been attributed EGF. It is a mitogen that stimulates the proliferation of different types of cells, especially fibroblasts and epithelial cells. During development, EGF modulates growth and differentiation of thymocytes, in the passage from double-negative to the double-positive (CD4+/CD8+) stage. It drives neuroglia production at the expense of neuron formation,promotes epithelization and inhibits adipocyte maturation . In the adult, EGF plays a role I mammary gland lactogenesis . It also causes fibroblast mitosis, extracellular matrix dissociation, and migration.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for EGF has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any EGF present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for EGF is added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of EGF bound in the initial step. The color development is stopped and the intensity of the color is measured.
