Description
Introduction: Growth differentiation factor-9 (GDF-9) is an oocyte-derived growth factor and a member of the transforming growth factor- (TGF-) superfamily that includes TGF-, activin, and bone morphogenetic proteins (BMPs). GDF-9 is indispensable for the development of ovarian follicles from the primary stage, and treatment with GDF-9 enhances the progression of early follicles into small preantral follicles. Similar to other TGF- family ligands, GDF-9 likely initiates signaling mediated by type I and type II receptors with serine/threonine kinase activity, followed by the phosphorylation of intracellular transcription factors named Smads.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to GDF-9. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific for GDF-9 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 GDF-9, 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 GDF-9 in the samples is then determined by comparing the O.D. of the samples to the standard curve