Adam E. Cohen
Physical probes of biological systems

Our effort is split between developing new physical tools to probe biological molecules, and using our tools to make new measurements. We choose problems by looking in unexplored regimes of time and space; we combine nanofabrication, lasers, microfluidics, electronics, biochemistry, and computers to generate data; and we apply statistics and physical modeling to understand the data. Current projects in the lab are geared toward trying to control molecules and cells in new ways. We are working in three general areas: 1) engineering the 3-dimensional shape of electromagnetic fields to interact with molecules in new ways, e.g. to excite molecules of only a single chirality in the presence of an excess of their mirror-image brethren. 2) controlling the position of an individual molecule by developing an Anti-Brownian Electrokinetic trap (ABEL trap) that can suppress the Brownian motion of a single molecule in solution. 3) developing microfluidic technology to position millions of single cells into complex three-dimensional structures, with each cell patterned according to its function.

Publications:

A. E. Cohen and W. E. Moerner, "Controlling Brownian motion of single protein molecules and single fluorophores in aqueous buffer," Optics Express, 16, 6941-6956 (2008)

A. E. Cohen and W. E. Moerner, "Principal Components Analysis of shape fluctuations of single DNA molecules," Proc. Natl. Acad. Sci. USA, 104, 12622-12627 (2007)

A. E. Cohen and W. E. Moerner, "Suppressing Brownian motion of individual biomolecules in solution," Proc. Natl. Acad. Sci. USA, 103, 4362-4365 (2006)

A. E. Cohen and Shaul Mukamel, "Resonant enhancement and dissipation in nonequilibrium van der Waals forces," Phys. Rev. Lett. 91, 233202 (2003)

A. E. Cohen and Shaul Mukamel, "A mechanical force accompanies fluorescence resonance energy transfer (FRET)," J. Phys. Chem. A 107, 3633 - 3638 (2003)