EPR spectroscopy is the gold standard for characterization of electronic structure of chemically reactive species with unpaired electrons. On systems that cannot be crystallized it may also be the best technique for determining spatial structure close to the paramagnetic centre. In the context of catalysis we perform such studies on structure of reactive species.
In structural biology, EPR spectroscopy can be combined with site-directed spin labelling to characterize systems that are too large for high-resolution NMR and not or not fully accessible to x-ray crystallography. We mainly work on protein-RNA complexes, membrane proteins, and intrinsically disordered proteins.