Applying Ligands to B Cell Receptors by Microfluidics

J. Christopher Love1, Yuan Gong1, and Eliseo Papa2. (1) Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Bldg. 66-456, Cambridge, MA 02139, (2) Health Sciences and Technology, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139

Microfluidic systems provide a unique set of tools for manipulating the environment of live cells while under continuous observation by optical microscopy. This talk will describe the use of a simple microfluidic system to follow the activation of B cells upon exposure to subsaturating doses of ligands by fluidic switching. The timing and sequence of these pulses makes it possible to observe temporally-distinct populations of receptors. It is possible to track the rearrangement and internalization of surface-expressed B cell receptors (BCRs) on primary na´ve B cells. Ratiometric imaging also allows kinetic measurements of the activation following stimulation.