Description
Introduction: Nerve growth factor (NGF), is a small secreted protein which induces the differentiation and survival of particular target neurons (nerve cells). NGF is a protein that consists of 3 types of polypeptide chains -- alpha, beta and gamma -- that interact to form the protein. The NGF beta chain (NGFB) is solely responsible for the nerve growth stimulating activity of NGF. The NGFB gene is in chromosome band 1p22. An ointment containing NGF has been reported to help heal bedsores. NGF is critical for the survival and maintenance of sympathetic and sensory neurons. NGF is released from the target cells, binds to and activates its high affinity receptor (TrkA), and is internalized into the responsive neuron. There are some data that show that NGF can be transported from the axon tip to soma, but it is unclear if this is necessary for effective cell signalling; in fact there are data showing that it is not. What is clear is that NGF binding and activation of TrkA is required for NGF-mediated neuronal survival and differentiation. NGF binds at least two receptors on the surface of cells which are capable of responding to this growth factor, TrkA and the LNGFR.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to NGF. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific for NGF 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 NGF, 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 NGF in the samples is then determined by comparing the O.D. of the samples to the standard curve