Ibrahim I. Cissé

Research Interests

The Cissé biophysics laboratory uses physical techniques to visualize weak and transient biological interactions, to study emergent phenomena in live cells with single molecule sensitivity.

The cell, the elementary unit of life, is a self-organized physical system of biological macromolecules. The organization and dynamics within are often regulated through complex rules involving low affinity, highly dynamic biomolecular interactions said to be “weak and transient.” Detecting and quantifying weak and transient interactions remains, however, a fantastic challenge.

Of particular interest to our group are collective behaviors that emerge from weak and transient biological interactions in living cells. For instance in high order organisms like humans, we understand very little of how transcription, the first step in the central dogma of biology – that DNA makes RNA (and RNA makes Proteins) – is carried out at the cellular level. Complex behaviors involving transient spatiotemporal clustering of molecular enzymes control genome regulation in ways that only now are we able to visualize.

Our approach is to develop and use highly sensitive experimental techniques capable of detecting and quantifying in a meaningful manner weak and transient biomolecular interactions. We have developed biophysical tools to measure weak and transient interactions both among isolated biomolecules (in vitro), and directly inside individual living cells with single-molecule sensitivity. Currently, we set out to understand what roles weak and transient interactions play in regulating genomic processes and nuclear organization at the single-cell level.

Biographic Sketch

Prof. Cissé joined the Department of Physics at MIT in January 2014, from HHMI’s Janelia Farm Research Campus where he has been in the Transcription Imaging Consortium since January 2013. Prior to this, he was in Paris from January 2010 to December 2012, at Ecole Normale Supérieure de Paris, jointly in the departments of Physics and Biology, as a Pierre Gilles de Gennes fellow and a European Molecular Biology Organization long-term fellow. He received his PhD from the Physics Department at the University of Illinois at Urbana-Champaign in December 2009. His graduate research in single-molecule biophysics was done in the lab of Taekjip Ha, focusing on weak and transient interactions in vitro. He received his B.S. in Physics in 2004 from North Carolina Central University, and during that time he was investigating packing of ellipsoids using M&M candies with Paul M. Chaikin. Ibrahim is native of Niger, where he lived before moving to the US for college.