预期应用
ELISA法定量测定大鼠血清、血浆、细胞培养物上清或其它相关液体中 sP-selectin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sP-selectin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sP-selectin抗原、生物素化的抗大鼠sP-selectin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sP-selectin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 rat soluble P-selectin (sP-selectin) concentrations in cell culture supernates, serum, and plasma.
Introduction
P-selectin is the largest of the known selectins at 140kDa. It contains nine consensus repeats (CR) and extends approximately 40 nm from the endothelial surface. Other names for P-selectin include
CD62P, Granule Membrane Protein 140 (GMP-140), and Platelet Activation-Dependent Granule to External Membrane Protein (PADGEM). P-selectin is expressed in a-granules of activated platelets and granules of endothelial cells. Within minutes of stimulation of the endothelial cells by inflammatory mediators such as histamine, thrombin, or phorbol esters, P-selectin is surface-expressed. Expression of P-selectin also occurs from the surgical trauma endured during preparation of the tissues for intravital microscopy. The expression is short-lived, reaching its peak
after only ten minutes. Additional synthesis of P-selectin is brought about within two hours by cytokines such as interleukin-1 (IL-1) or tumor necrosis factor a (TNF-a). The primary ligand for
P-selectin is PSGL-1 (P-selectin glycoprotein ligand-1) which is constitutively found on all leukocytes. Other ligands for P-selectin include CD24 and uncharacterized ligands. The transient
interactions between P-selectin and PSGL-1 allow leukocytes to roll along the venular endothelium. Accordingly, P-selectin is largely responsible for the rolling phase of the leukocyte adhesion cascade. P-selectin can also mediate capture when L-selectin is not present.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for sP-selectin has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any sP-selectin present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for sP-selectin 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 sP-selectin bound in the initial step. The color development is stopped and the intensity of the color is measured. | 
