switchSENSE® for the characterization of polymerases
switchSENSE® is the first and only chip-based biosensor that employs electro-switchable biosurfaces (ESB) for the biophysical analysis of molecular interactions. Two signals are analyzed simultaneously to follow interactions between proteins and nucleic acids and to monitor polymerization or nuclease activity: The molecular ruler is used to gauge the extension of DNA/RNA primers in real-time during polymerization or nuclease activity. A second, dynamic measurement mode is used to monitor the binding of proteins to nucleic acids. High frequency alternating potentials induce an oscillation of the nucleic acid nanolevers. When proteins bind to the nucleic acid probes, hydrodynamic friction increases and the switching speed slows down. Hence, association and dissociation kinetics, affinities, the number of bound enzymes and even the location of the enzyme along the nucleic acid strand can be analyzed by monitoring the switching speed in real-time.