Laboratory of Single Molecule Biophysics

Research Interests

We do experiments on linear DNA molecules modified with functionalized, neutrally-buoyant superparamagnetic beads on each end. One bead is fixed to a chemically-modified stiff glass pipette while the other bead is suspended in the buffer and acted upon by a magnetic force generated by a small bar magnet built into our custom 3D-printed sample cell. The force on this bead is adjusted by changing the distance between it and the magnet. Movies of such experiments are analyzed using image processing methods, which allow us to extract the extension of the DNA and the force it's being pulled with. Using a buffer exchange system incorporated into our sample cell, we can introduce DNA-binding proteins of interest allowing them to bind to the DNA. When proteins bind and produce changes in the tether's extension, say by forming loops in the DNA, the resulting force-extension curves can be used to infer valuable information about the nature of the underlying DNA-protein interaction.

We are also interested in developing statistical mechanical models of single molecule experiments. In general, I have an interest in applying ideas from condensed matter physics to better understand how genetic processes work on a variety of scales.

Teaching

Selected Publications

Former
Lab Members