Xiao-Lun Wu

Address:
Department of Physics and Astronomy

Phone: 412-624-0873
Fax: (412); 624-9163
Email: xlwu@pitt.edu
Homepage: Visit

Background:

When and where you received your PhD
Cornell Univeristy, 1987

Where you did your postdoc:
Exxon Research and Engineering Co. and Princeton University

Research:

We are using experimental and theoretical tools developed in physics to study biological systems. Current research in the laboratory includes the study of synaptic vesicle motion in hippocampus nerve cells using fluorescence correlation spectroscopy (FCS); and fluorescent recovery after photobleaching (FRAP);.1 New theoretical models2 are investigated to explain the observed vesicle transport in these ultra-fine nerve terminals. Our lab also heavily engaged in the study of bacterial swimming using optical traps. Propulsion of bacteria by rotary molecular motors and helical flagella is known and is subject to intense mathematical analysis. However, measuring mechanical properties of bacterial swimming apparatus turns out to be very difficult. This difficulty has recently been overcome in our laboratory using an optical tweezers and an imposed flow field. Different swimming properties, such as the torque and thrust generated by the molecular motor, are measured one bacterium at a time and over a large population.3 Using a fluorescence labeling techniques, we also investigated gene expression noise and such a noise on the survival of a bacterial population under severe phage pressure.

1. Probing vesicle dynamics in single hippocampal neurons, M. Shtrahman, C. Yeung, D.W. Nauen, G.-q. Bi, and X.L. Wu, Biophys. J. 89, 3615 (2005);.
2. Stick-and-diffuse or caged diffusion, a comparison of two models of synaptic vesicle dynamics, C. Yeung, M. Shtrahman, and X.L. Wu, submitted to Biophys. J. (2006);.
3. Swimming efficiency of bacterial Escherichia coli, S. Chattopadhyay, R. Moldovan, C. Yeung, and X.L. Wu, to appear in PNAS (2006);.