Detweiler, Charles (NIEHS)
Electron Spin Resonance (ESR) is an universal, specific tool for the detection of free radicals in biological systems. Its application to the investigation of free radicals from whole animals, organs, and cells has been made possible by the spin-trapping technique. In a Spin-trapping experiment, a spin trap such as DMPO (5,5-dimetryl-1-pyrroline N-oxide) reacts specifically with one or more types of free radical to form radical-derived nitrone adducts that are much more stable than the original free radicals. In decades of investigation, very few artifacts have been discovered with the use of nitrone spin traps like DPMO. Unfortunately, due to technical limitations inherent in ESR detection, neither the tissue nor cellular distribution of free radicals has ever been determined with ESR. This invention takes advantage of the highly antigenic nature of the nitrone adducts of proteins and aim at developing specific antibodies to nitrone adducts that can be used in western blotting and enzyme immunoassays (EIA). This would allow the visualization of the distribution of free radical damage to tissues and cells. This methodology is both broad and free radical specific, and should open free radical investigations to biomedical investigations in ways never before possible.
- The antibodies for spin traps, nitrons adducts, and corresponding hydroxylamines of the radical adducts can be used for detecting free radicals and their distributions in tissues and cells, allowing possibility for clinical applications.
- The cost of using this method to detect free radicals is substantially cheaper than current ESR methodologies. For example, a western blot assay can be done for a few hundred dollars, whereas an ESR spectrometer can easily cost upwards of $250,000. In addition, detection of nitrone adducts using immunohistological techniques would broaden the scope of free radical detection by providing images of the distribution of free radical damage within tissue and cells.