特 异 性： 人IGF-1
检测标本： 细胞培养液、体液、血清和组织匀浆等
检测范围： 62.5pg/ml→4000pg/ml
预期应用
ELISA法定量测定人血清、细胞培养物上清或其它相关液体中IGF-I含量。
概述
胰岛素样生长因子 1(Insulin likegrowthfactor1,IGF－1),又称生长激素刺激素c，是一种相对分子质量为7600的单链非糖多肽。最先发现它的功能是其能调节体细胞生长，后又发现它是一种重要的细胞生长,分化过程中的调节蛋白。 在哺乳动物中，成熟的IGF－1结构相当保守，在人、猪、牛以及犬类动物中其蛋白质结构100%相同。IGF－1主要由肝脏分泌，以与IGFBP组成结合物的形式存在于血液和其它体液中。人胰岛素样生长因子-I其氨基酸序列与大鼠及人比较，分别有99%和94%相同。
实验原理
本试剂盒应用双抗体夹心酶标免疫分析法测定标本中IGF－1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IGF－1抗原、生物素化的抗人IGF－1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IGF－1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 human IGF-1 concentrations in cell culture supernates, serum, and plasma.
Introduction
Insulin-like Growth Factor I (IGF-I), also known as somatomedin C, is a member of the insulin
superfamily. It was originally discovered as a mediator of growth hormone actions on somatic cell growth, but has also been shown to be an important regulator of cell metabolism, differentiation and survival. IGF-I is synthesized as a preproprotein that is proteolytically cleaved to generate the mature protein linked by three disulfide bonds. Mature IGF-I is highly conserved among mammals, with 100% sequence identity between the human, bovine, porcine, equine and canine proteins. Mature mouse IGF-I is a non-glycosylated, 70 amino acid (aa) residue secreted polypeptide that is derived from either a 153 aa or a 159 aa preproproteins. It shares 99% and 94% aa sequence identity with rat and human IGF-I, respectively. IGF-I is synthesized in the liver and multiple other tissues. It is found in blood and other body fluids as a complex with specific high affinity IGF binding proteins (IGFBP-1 to -6). The IGFBPs are expressed in specific patterns during development. They are modulators of IGF actions, which control IGF bioavailability to specific cell-surface receptors. Their functions are further regulated by IGFBP proteases, which proteolytically cleave the IGFBPs to lower the affinity with which they bind IGFs and increase IGF bioavailability. Some IGFBPs also have IGF-independent effects on cell functions. IGF-I circulates primarily as a ternary complex with IGFBP-3 or IGFBP-5 and the acid-labile subunit (ALS). Some IGF-I is also present in binary complexes with other IGFBPs. Whereas the ternary complexes are generally restricted to the vasculature, the binary complexes freely enter the tissues.
IGF-I actions are mediated by two type I transmembrane receptor tyrosine kinases: the IGF-I receptor (IGF-I R), and the insulin receptor (INS R) that exists in two alternatively spliced isoforms (INS R-A and -B). Both IGF-I R and INS R share a highly homologous structure and are ubiquitously expressed. Each receptor is derived from a precursor that is proteolytically cleaved into two disulfide-linked subunits: the extracellular _- and the transmembrane _-subunits. Functional IGF-I receptors are tetrameric glycoproteins composed of two disulfide-linked IGF-I Rs or disulfide-linked hybrids of one IGF-I R and one INS R. Whereas IGF-I binds with high-affinity to homodimeric IGF-I R and heterdimeric IGF-I R:INS R-A or –B hybrids, high-affinity binding of insulin is observed only with dimeric INS R or IGF-I R:INS R-A hybrid but not with IGF-I R:INS R-B hybrid. The signaling responses from the various receptors are different depending whether insulin or IGF-I is used as the activating ligand. This kit demonstrates significant cross-reactivity with rat IGF-I and has been validated for the determination of relative mass values for natural rat IGF-I in cell culture supernates, rat serum and plasma. The amount of natural rat IGF-I measured is expressed as mouse IGF-I equivalent.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IGF-1 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any IGF-1 present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for IGF-1 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 IGF-1 bound in the initial step. The color development is stopped and the intensity of the color is measured. | 
