ELISA法定量测定小鼠血清、血浆或其它相关液体中内脂素含量。

本试剂盒应用双抗体夹心酶标免疫分析法测定标本中内脂素水平。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内脂素、生物素化的抗小鼠内脂素抗体、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内脂素呈正相关。用酶标仪在450nm波长下测定吸光度（OD值），计算样品浓度。

This immunoassay kit allows for the specific measurement of Mouse visfatin concentrations in cell culture supernates, serum, and plasma.

Visfatin, an adipocytokine that is highly enriched in the visceral fat of both Mouses and mice and whose expression level in plasma increases during the development of obesity. Visfatin corresponds to pre-B cell colony-enhancing factor (PBEF), a 52-kD cytokine expressed in lymphocytes. The gene encoding PBEF was originally isolated from an activated lymphocyte cDNA library.The 3-prime UTR of PBEF contains several TATT motifs, destabilizing sequences characteristic of cytokine messages. The deduced 473-amino acid protein has a calculated molecular mass of 52 kDa. PBEF has a hydrophobic N terminus, 2 N-glycosylation sites, several putative phosphorylation sites, and 6 cysteines. Northern blot analysis detected transcripts of about 2.0, 2.4, and 4.0 kb in all tissues examined, with highest expression in liver, followed by muscle.

Although PBEF lacks a typical signal sequence for secretion, transfected COS-7 and mouse embryonic fibroblasts secreted PBEF into the culture medium. Samal et al.  found that recombinant PBEF secreted from transfected COS-7 and mouse embryonic fibroblasts was not itself active in a pre-B-cell colony formation assay, but it synergized the pre-B-cell colony formation activity of stem cell factor and interleukin-7. Jia et al. found that PBEF is an inflammatory cytokine that plays a requisite role in the delayed neutrophil apoptosis of sepsis. Visfatin exerted insulin-mimetic effects in cultured cells and lowered plasma glucose levels in mice. Mice heterozygous for a targeted mutation in the visfatin gene had modestly higher levels of plasma glucose relative to wild type littermates. Surprisingly, it was found that visfatin binds to and activates the insulin receptor . Recently, Chen et al. found that plasma level of visfatin in patients with type 2 diabetes mellitus was elevated , suggesting that measurement of plasma visfatin provides a relevant tool for understanding metabolic diseases.

This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for visfatin has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any visfatin present is bound by the immobilized antibody. An enzyme-linked polyclonal antibody specific for visfatin 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 visfatin bound in the initial step. The color development is stopped and the intensity of the color is measured.