Physics Colloquium
Friday, October 10th, 2003 4 P.M.

Jim Valles

Department of Physics,
Brown University

Manipulating Cells with Static Magnetic Field

The materials in cells are primarily diamagnetic and thus, respond weakly to 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. First, 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.  Second, we have applied magnetic forces and torques on Paramecium that change their swimming behavior.  I will describe our efforts to use these effects to study the sensitivity of Paramecium to the body force of gravity.

Refreshments 3:30 P.M. Room E200 Math/Science Center