预期应用
ELISA法定量测定人血清、血浆、细胞培养物上清或其它相关液体中TSP-1含量。
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TSP-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TSP-1抗原、生物素化的抗人TSP-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TSP-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 TSP-1 concentrations in cell culture supernates, serum, and plasma.
Introduction
Thrombospondin-1 (TSP-1) is a 150 - 180 kDa charter member of the thrombospondin family of extracellular matrix proteins.1 - 4 Human TSP-1 is synthesized as an 1170 amino acid (aa) precursor that contains an 18 aa signal sequence and 1152 aa mature molecule. The mature molecule has been described as containing three distinct regions that create the shape of a dumbbell. There is an intital, 140 aa N-terminal laminin G-like globular region that binds heparin (aa 19 - 258). This is followed by an extended, central collagen-binding region that contains one type C von Willebrand factor domain, plus three TSP type I and three TSP type II (or EGF-like) domains (aa 259 - 712). The type I repeats have multiple functions. They bind to type IV collagen, laminin, fibronectin and CD36. They also contain a recognition site for C-mannosylation on Trp. Finally, a type I KRFK motif induces the release of mature TGF-β from LAP. This is an effect not found in TSP-2. The function of the type II repeats in unclear. The C-terminus (aa 713 - 1170) appears as a large globule with two halves; one calcium-binding region (aa 713 - 950) with seven Asp-rich TSP type III domains, and one terminal region (aa 951 - 1170) with TSP-unique motifs. This end terminal region is believed to mediate CD47 and cell binding.2 - 4 TSP-1 is secreted as a disulfide-linked 450 kDa homotrimer. The cysteines responsible lie just N-terminal to the first type I TSP repeat. Mature human TSP-1 is 61% aa identical to human TSP-2. It is also 95%, 97% and 95% aa identical to mouse, dog and rat TSP-1, respectively.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal
antibody specific for TSP-1 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any TSP-1 present is bound by the immobilized antibody. An
enzyme-linked monoclonal antibody specific for TSP-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 TSP-1 bound in the initial step. The color
development is stopped and the intensity of the color is measured.
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