ESPCI web site
Some experiments with magnetic tweezers
Magnetic tweezers are an easy to use micromanipulation tool that works in the pN force range. It is in particular very convenient to study nucleic acid mechanical properties in different contexts. It is indeed possible to use those properties to get quantitative informations on any phenomenon that affect the mechanics of nucleic acids like molecular motors tracking along a stretched DNA molecule or the binding of an interacting protein or the binding of a complementary nucleic acid strand. We will show somes examples of those experiments and present our recent spatiotemporal improvement of the setup that allow us to measure subnanometer phenomena like the detection of an helicase step or to measure the fast binding of oligonucleotides as small as 5 bases without any fluorescence.
Refs :
Rieu et al "Stereo Darkfield Interferometry : a versatile localization method for subnanometer force spectroscopy of single molecules and 3D-tracking of single cells." arXiv preprint arXiv:2008.02898 (2020).