Investigating the intermolecular forces in a DNA double helix is of fundamental importance in biophysical chemistry. Using a recently developed force-induced remnant magnetization spectroscopy (FIRMS) technique, we obtained the binding forces of a series of DNA duplex, with a force resolution of better than 2 pN. Experimentally, one of the DNA strand in the duplex was immobilized on the surface and the other strand was labeled by magnetic particles. An external mechanical force with increasing amplitude was used to dissociate the interactions between the two strands. The magnetic signal was monitored by an atomic magnetometer. With the high force resolution, we were able to resolve two DNA interactions that differ by only one base. The binding forces were calibrated and the values were consistent with the literature. Furthermore, we observed that the binding force of DNA double strands depends on the position of the mismatching base.

High-resolution force spectroscopy for investigating DNA double strand interactions

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.