Spectral-Spatial Electron Paramagnetic Resonance Imaging (EPRI) in Skin Biopsies at 9.5 GHz

EPR spectroscopy can quantitatively detect free radicals with high specificity and sensitivity in biological samples. However, the natural free radical concentration in biological systems is usually too low for giving sufficient signal intensity which is necessary for EPR. In practice it is almost always necessary to use the indirect spin-trap method to detect radical spin adducts, which are in most cases nitroxide free radicals. The success of EPR-based studies relies heavily on the use or spin traps or the ability to follow the kinetics of nitroxides (1 ). Nitroxides are sensitive to motion, polarity, structural order and fluidity, oxygen tension, pH, and participate in one electron transfer reactions (2 ).