Single-Molecule Visualization of B-Z Transition in DNA Origami Using High-Speed AFM.

To study the physical properties of molecules and their reaction processes, direct visualization of target molecules is one of the straightforward methods. Atomic force microscopy (AFM) enables the direct imaging of biomolecules under physiological conditions at nanometer-scale spatial resolution. In addition, using the DNA origami technology, the precise placement of target molecules in a designed nanostructure has been achieved, and the detection of the molecules at the single-molecule level has been realized. DNA origami is applied for visualizing the detailed movement of molecules combining with high-speed AFM (HS-AFM), which enables the analysis of the dynamic movement of biomolecules in a subsecond time resolution.Here, we describe the combination of the DNA origami system with HS-AFM for the imaging of rotation of dsDNA originated from B-Z transition. The rotation of dsDNA during B-Z transition is directly visualized in a DNA origami using the HS-AFM. These target-oriented observation systems serve to the detailed analysis of DNA structural changes in real time at molecular resolution.