Vascular endothelial growth factor （VEGF），also known as vascular permeability factor （VPF） or vasculotropin，is a homodimeric 34 42kD，heparin-binding glycoprotein with potent angiogenic，mitogenic and vascular permeability-enhancing activities specific for endothelial cells. The amino acid sequence of VEGF exhibits primary structural，as well as limited amino acid sequence，homology with that of the A and B chains of PDGF. All eight cysteine residues involved in intra- and inter-chain disulfide bonds are conserved among these growth factors. A cDNA encoding a protein having a 53%aa sequence homology in the PDGF-like region of VEGF has been isolated from a human placental cDNA library. This protein，named placenta growth factor （PlGF），is now recognized to be a member of the VEGF family of growth factors. Based on its homology with VEGF，PlGF was also proposed to be an angiogenic factor. Two receptor tyrosine kinases have been described as putative VEGF receptors. Flt-1 （fms-like tyrosine kinase），and KDR （kinase-insert-domain-containing receptor） proteins have been shown to bind VEGF with high affinity.Sample Type：Cell culture supernatants，serum，plasma，and tissueIntended Use：The Rat VEGF BioAssay ELISA Kit is an enzyme-linked immunosorbent assay for the quantitative detection of Rat VEGF concentrations in cell culture supernatants，serum，plasma，and tissue.Sensitivity：4pg/mlRange：15.625-1000pg/mlSpecificity：Recognizes rat VEGF.Sample Volume：100ul/wellTest Principle：This assay employs the Sandwich immunoassay technique. An anti r VEGF monoclonal coating antibody is adsorbed onto microwells. VEGF present in the sample or standard and Biotinylated anti VEGF antibody binds to antibodies adsorbed to the microwells. Following incubation unbound sample or standard and Biotinylated anti VEGF antibody are removed during a wash step. A Streptavidin-HRP is added and binds to Biotinylated anti VEGF antibody. Following incubation unbound Streptavidin-HRP is removed during a wash step. A colored product is formed in proportion to the amount of VEGF present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450nm. A standard curve is prepared from seven VEGF standard dilutions and VEGF sample concentration determined.Kit Components：Aluminium pouches with a Microwell Plate： 8x6Standard： 1xVialBiotinylated antibody： 1xVialStreptavidin-HRP： 1xVialAssay Buffer （25ml/Vial）： 1xVialWash Buffer Concentrate 20x （30ml/Vial）： 1xVialTMB Substrate Solution： 1x6mlStop Solution （12ml/Vial）： 1xVialPlate Covers- Adhesive strips： 2xstripsInstruction： 1xStorage and Stability：Store powder at 4°C liquid at -20°C. Store other components at 4°C. Stable for at least 6 months For maximum recovery of product，centrifuge the original vial after thawing and prior to removing the cap.
