I have been a University Lecturer in Oxford Physics since 2000. My research group works on the physics of the Large Molecular Machines that perform most of the essential processes of life. We currently focus on Rotary Molecular Motors, in particular the Bacterial Flagellar Motor and F1FO ATP-synthase. The aim is to try and understand how these living machines work.
We use a range of techniques. Molecular motors are tens of nanometres in size, and we measure their motion using novel forms of light microscopy to follow visible "handles" such as sub-micron gold or polystyrene spheres and rods, and single fluorescent molecules. We measure the position of the handles with nanometre and sub-millisecond resolution using fluorescence microscopy, laser dark-field microscopy and laser interferometry. Optical tweezers (3-D laser traps) and magnetic tweezers are used to push single motors around. We also use single-molecule fluorescence microscopy to detect separate components of the motors and assess how they interact with each other.
By measuring the torque generated by the motors under all sorts of different conditions, we aim to arrive at a model of how they work. We are also interested in how the motors are built and maintained in living cells, how they are controlled, and in the case of the flagellar motor, how they make bacteria swim
We also develop new techniques in fields including medical diagnostics, digital holographic microscopy, lipid bilayer systems for single-molecule microscopy and synthetic biology. We have numerous collaborations in fields including microbiology, molecular biology and structural biology.