Physics Colloquium, October 17, 2006
Cell Biology in Many Tesla James Valles

Brown University

The materials in cells are primarily diamagnetic and thus, respond weakly to terrestrial magnetic fields. Nevertheless, magnetic fields are available that are sufficiently intense to align biopolymers such as microtubules and biomolecular assemblies such as cell membranes. In addition, common organic materials can be magnetically levitated. We are exploiting these weak intrinsic responses to manipulate cellular processes. I will describe our work on two systems. We have found that magnetic fields alter the geometry of the early cell division geometry of frog eggs. Our efforts to determine the mechanism have led to new insight into the factors that control the nominal cell division geometry. Most recently, we have applied magnetic forces and torques on the swimming single-cell organism, Paramecium, which substantially change its swimming direction and speed. I will describe our efforts to use these effects to study the origins of its remarkable sensitivity to the body force of gravity.

Dr. Valles' Web Site

4:00 p.m., Physics Research Building (PRB), Room 1080

Reception at 3:45 p.m., Atrium, PRB