Cohen Lab

Physical tools to study molecules, cells, and organisms

We invent new physical tools to probe biological structures. Then we use our tools to make new measurements. We choose problems by looking in unexplored regimes of time and space; we combine protein engineering, lasers, nanofabrication, microfluidics, electronics, biochemistry, and computers to generate data; and we apply statistics and physical modeling to understand the data.



Research Areas


Previous projects

Optical chirality, trapping single molecules, microbial and molecular motion in mucus, photochromic FRET, nonequilibrium van der Waals forces.



eFRET GEVIs make a flashing rainbow (8/2014)

Peng and Yongxin's paper describes a new approach to voltage imaging: they use voltage-dependent fluorescence resonance energy transfer (electrochromic FRET) from a fluorescent protein to a microbial rhodopsin to make multicolored genetically encoded voltage indicators (GEVIs). Now we can light up neurons in technicolor!

Pleasant Surprises (8/2014)

Adam won three nice prizes: The Blavatnik Award for Young Scientists, an NIBIB Nagy New Investigator award, and the Pure Chemistry award from the American Chemical Society. Special thanks to the many students and postdocs whose hard work these awards recognize!

All-optical electrophysiology (6/2014)

Congratulations to Daniel, Yongxin, and the whole team for their major paper on all-optical electrophysiology, published in Nature Methods.  Watch supplementary movies 4 - 6 to  make your neurons light up!

Bringing Bioelectricity to Light (6/2014)

Veena and Adam wrote a review in Annual Reviews of Biophysics describing how one should think about electrophysiology measurements when the actuators and reporters are transmembrane proteins rather than physical electrodes.  Bioelectric phenomena are wondrous and varied!

Weintraub Award to Daniel Hochbaum (2/2014)

Daniel Hochbaum has been awarded the Harold M. Weintraub Graduate Student Award for outstanding achievement during graduate studies in the biological sciences.  Not bad for a physicist!

Absolute Voltage (2/2014)

Jen and Veena discovered how to measure absolute membrane voltage via rhodopsin photocycle dynamics.  Read about it in Biophysical Journal.  See also a nice commentary from John Spudich.  Cheers to Jen and Veena!

A flash of memory! (1/2014)

Veena and Daan's paper on Flash Memory came out in JACS.  They showed how one could store a long-lasting photochemical imprint of neuronal activity in a microbial rhodopsin. This suggests a path to whole-brain neural recording, though there's still a lot of work to do.

Spiking HEKs (1/2014)

We made a line of non-fluorescent HEK cells that produce spontaneous electrical spikes in confluent culture.  They produce beautiful waves and spiral patters of electrical activity.  Shocking!  These are great for testing prospective fluorescent voltage indicators.  The paper is in PLoS One. Congratulations Jeehae and Kit!

Welcome to Xin and Yoav (12/2013)

Two new postdocs joined the lab.  Yoav comes from the lab of Adi Mizrahi at Hebrew U.  Yoav will be looking at optical electrophysiology in mouse brains.  Xin Tang comes from the lab of Taher Saif at UIUC.  Xin will study bioelectric and biomechanical effects outside the nervous system.  Welcome both!

Doctor! Doctor! (10/2013)

Congratulations to Jen and Min Ju for defending their PhD theses! Jen's topic was "Dynamics in Biological Soft Materials," and Min Ju's was "Trapping and Manipulating Single Molecules of DNA". We will miss you both! 

New faces in lab (9/2013)

Jonathan Gootenberg joins as a rotation student, continuing the proud tradition of our lab importing our brains from MIT.  Miao-Ping Chien joins as a postdoc from UCSD.  Miao-Ping comes from Nathan Gianneschi's Lab at UCSD, where she worked on stimulus-responsive nanomaterials and drug delivery.  Here she'll be helping us see what we feel.  Shan Lou joins as a postdoc from Qiufu Ma's lab at the Dana Farber Cancer Institute, where she worked on the sense of touch.  Here she will be imaging electrical activity in peripheral nerves.  Welcome all!

Check out our kinky genes! (8/2013)

Alex's paper on Euler buckling and nonlinear kinging in double-stranded DNA was just published in Nucleic Acids Research. Nice work, Alex!

Adam appointed HHMI Investigator (5/2013)

The Howard Hughes Medical Institute selected Adam as one of its new investigators. Thank you Mr. Hughes!

Alex defends thesis (5/2013)

Alex passed his thesis defense with an elegant discussion of the ABEL trap, and also recent work on DNA mechanics. Congratulations Dr. Fields!

Welcome to Vedha Nathan (5/2013)

Vedha Nathan is joining the lab as a Research Assistant. She comes with many years of experience working in Howard Berg's lab. Welcome Vedha!

Arch photophysics (3/2013)

Archaerhodopsin 3 (Arch) acts as a fluorescent reporter of membrane voltage. But how does it work? Dougal, Veena, and Hohjai elucidate the mechanism in PNAS.

Twisty nanowires (1/2013)

Yiqiao's paper on chiroptical effects in twisted nanowire plasmonic oscillators came out in Applied Physics Letter. A nice twist to finish your thesis.

Welcome Maggie! Thank you Jeff! (1/2013)

Maggie Kenar is taking over the administrative management of the lab from Jeff Fosdick. Thank you for all your help Jeff, and welcome to the family, Maggie.

Doctor, Doctor! (12/2012)

Congratulations to Yiqiao and Nan for successfully defending their PhD theses. First two students to graduate from the group. Nice work, guys!!

Popular Scientist (10/2012)

Adam features in this month's issue of Popular Science as one of their "Brilliant 10". I never won a popularity contest before!

Optimal tracking of a Brownian particle (9/2012)

Congratulations to Alex on his recent paper in Optics Express! The paper explains the theory of how to do as good a job as possible tracking a dim, quickly diffusing object.

Nice dimples -- paper in JACS (8/2012)

Min Ju's paper on trapping single molecules in nanoscale dimples will appear as an article in JACS. Nice work Min Ju!



©2012 Adam E. Cohen