Description
Introduction: The angiopoietins are protein growth factors that promote angiogenesis, the formation of blood vessels from pre-existing blood vessels. All angiopoietins bind with similar affinity to an endothelial cell-specific tyrosine-protein kinase receptor. The mechanism by which they contribute to angiogenesis is thought to involve regulation of endothelial cell interactions with supporting perivascular cells. There are now four identified angiopoietins: Ang-1, Ang-2, Ang-3, Ang-4. Ang-1 is an angiogenic secreted protein that interact with endothelial specific Tie-2 receptor. Mouse and human Ang-1 have 98% identity. During embryonic development, Ang-1 binds and induces tyrosine phosphorylation of Tie-2. Ang-1 deficient mice mimic the phenotype exhibited by animals deficient in Tie-2. The role of Ang-1 in angiogenesis appears to be different from VEGF. Ang-1 is prominently expressed in the myocardium of atrium and ventricle, mesenchymal and smooth muscle cells surrounding most blood vessels, and lung.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to ANG-1. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific for ANG-1 and Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain ANG-1, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/- 2 nm. The concentration of ANG-1 in the samples is then determined by comparing the O.D. of the samples to the standard curve