Philippe Cluzel, who has drawn upon his grounding in both physics and biology to become an authority on the biophysics of single cells, has been appointed professor of molecular and cellular biology and Gordon McKay Professor of Applied Physics in Harvard University’s Faculty of Arts and Sciences (FAS) and School of Engineering and Applied Sciences, effective July 1.

Cluzel, 41, was previously associate professor of physics at the University of Chicago, where he has been on the faculty since 2000.

“Professor Cluzel has helped explain cells’ and organisms’ behavior and bodily structure by applying the principles of physics and engineering to biological systems,” says Jeremy Bloxham, FAS dean for the sciences. “At the University of Chicago he has shown himself to be an excellent mentor and a formidable instructor in both biology and physics. His surefootedness in both disciplines will put him at the hub of Harvard’s growing efforts in systems biology.”

At Harvard, Cluzel will be affiliated with the FAS Center for Systems Biology. Recent advances in molecular biology have given scientists a nearly complete catalog of the genes, RNA, and proteins of many species; systems biology seeks to explain how these parts interact to shape organisms’ structure, behavior, and evolution. In so doing, the field hopes to elucidate general principles that apply across species.

Among other topics, Cluzel has pioneered the macro-manipulation of individual molecules of DNA. He showed that stretching a strand of the genetic template by 1.7 times its natural relaxed length induced a new structure, called S-DNA. He has examined the system governing migration of E. coli bacteria towards chemical attractants — a process known as chemotaxis — as a model for the study of other cellular signaling.

Cluzel has also focused on how cells ignore background noise from ongoing cellular processes to pick out specific key signals related to cell growth, division, or death. By developing novel techniques to track single molecules, his group has eavesdropped on the activity of individual living cells in real time.

Cluzel’s research has used a few basic chemical reactions to map gene expression in bacteria. His group was the first to measure RNA synthesis in real time in living bacteria, a feat followed up on by other groups measuring RNA bursts during gene expression in individual cells.

Cluzel holds undergraduate and master’s degrees from Paris VI University and was awarded a Ph.D. from the Institut Marie Curie in Paris in 1996. He was a research associate at Princeton University from 1996 to 2000, when he joined the University of Chicago as an assistant professor. He was named associate professor at Chicago in 2007.