Thursday, 30 March, 2017
UTK Host: Dr. Mike Sepaniak, Professor of Chemistry
Speaker: Dr. Stephen Jacobson, Professor and Bair Chair
Department of Chemistry, Indiana University
Title: “Nanofluidic Devices for Single-Particle Analysis of Virus Assembly and Bacterial Development”
Abstract: We are developing micro- and nanofluidic devices to study virus assembly and bacterial development at the single-particle level with improved spatial and temporal resolution. Analysis of single particles provides powerful insight into biological processes that are often missed when a population is studied as an ensemble.
To characterize the assembly of Hepatitis B Virus dimers into T = 3 and T = 4 symmetry capsids, we are using resistive-pulse sensing as a label-free, nondestructive technique. This single-particle method permits real-time detection of both capsid formation and intermediate depletion and has sufficient sensitivity to monitor assembly well below the pseudo-critical dimer concentration. At low dimer concentrations, the early steps of assembly are rate- and product-limiting, whereas at high dimer concentration, incomplete particles assemble rapidly, become kinetically trapped, and slowly anneal into capsids. We are also able to capture how potential antivirals accelerate assembly and lead to misformed particles.
To study development and aging in bacteria, we have integrated nanochannel arrays into a microfluidic platform that physically trap bacteria. The nanochannels confine growth of bacteria in one dimension, and when coupled with optical microscopy, individual bacteria are tracked with improved temporal and spatial resolution. With nanochannels having various widths, we are able to study a number of bacteria strains, e.g., Bacillus subtilis and Caulobacter crescentus, and observe them over multiple generations. Consequently, we can determine rates of cell growth and division, monitor accumulation of cellular damage, and observe epigenetic effects.
Biography: Stephen C. Jacobson is a Professor of Chemistry, holds the Bair Chair in Chemistry, and is currently the Chair of the Department of Chemistry at Indiana University (IU). He received a B.S. in mathematics from Georgetown University in 1988 and a Ph.D. in chemistry from the University of Tennessee in 1992. After graduate school, Stephen was awarded an Alexander Hollaender Distinguished Postdoctoral Fellowship at Oak Ridge National Laboratory (ORNL), and in 1995, he became a research staff member at ORNL. In 2003, Stephen joined the faculty in the Chemistry Department at IU. His research efforts are directed toward miniaturization of analytical instrumentation with an emphasis on micro- and nanofluidic devices. Stephen and his research group are actively working in the areas of microfluidic separations, nanofluidic transport, cancer screening, virus sensing and assembly, and bacterial adhesion, development, and aging.
for the 2017 Spring Chemistry Schedule.
Web Cast: This seminar is not web cast.