A beginner’s guide to surface plasmon resonance

Surface plasmon resonance (SPR) has emerged as a powerful optical detection technique for studying the binding behaviour of immobilized ligands and analytes in solution. The technique makes it possible to measure interactions in real time with high sensitivity. Over the past two decades, SPR has become the gold standard for studying biomolecular interactions in biomedical research and drug discovery. The interactions that can be studied are diverse and include protein–protein, protein–small molecule, protein–nucleic acid, protein–carbohydrate, lipid–protein, hybrid systems of biomolecules and non-biological surfaces. SPR allows researchers to determine which molecules interact, how strongly they bind and inform experiments using mutants, truncations or other variations to probe specificity. This article summarizes the principle and experimental set-up and illustrates the utility of SPR using the example of lipid–protein interactions.