Biosensor-Surface Plasmon Resonance: Label-Free Method for Investigation of Small Molecule-Quadruplex Nucleic Acid Interactions.

Biosensor-surface plasmon resonance (SPR) technology is now well established as a quantitative approach for the study of nucleic acid interactions in real time, without the need for labeling any components of the interaction. The method provides real-time equilibrium and kinetic characterization for quadruplex DNA interactions and requires small amounts of materials and no external probe. A detailed protocol for quadruplex-DNA interaction analyses with a variety of binding molecules using biosensor-SPR methods is presented. Explanations of the SPR method with basic fundamentals for use and analysis of results are described with recommendations on the preparation of the SPR instrument, sensor chips, and samples. Details of experimental design, quantitative and qualitative data analyses, and presentation are described. Some specific examples of small molecule-DNA quadruplex interactions are presented with results evaluated by both kinetic and steady-state SPR methods.