Speaker: Dr. Cullen R. Buie
Title: Microfluidic Bacterial Electrophenotyping
Date: Monday, March 23, 2015
Time: 3:30-5:00 pm (Refreshments- 3:30-4:00pm)
Location: Thorton Hall E304
Hosts: Nathan Swami (ECE) &
James Landers (Chemistry)
In microbiology the ability to obtain genetic information far outpaces our ability to obtain phenotypic (or physical) information. This is a critical limitation because in many cases it is difficult, if not impossible, to infer the function of genes in an organism from genetic information alone. For the advancement of biotechnology and healthcare it is necessary to assess the links between genotype and phenotype. We have developed microfluidic techniques that exploit electrokinetic phenomena to determine connections between cell electrophenotypes (i.e. electrical properties) and genetics. First, I will present a detailed theoretical model to investigate the effect of appendages such as pili on the dielectric polarization of bacteria. The results demonstrate an interesting interplay between soft layer conductivity and double layer conductivity on polarizability, subtleties often neglected in previous models. Next, we exploit sub-species level differences in cell surface polarizability in novel three dimensional insulator based dielectrophoresis (3DiDEP) systems. Lastly we have developed a rapid microfluidic assay to quantitatively measure electric field conditions required for electroporation. Our rapid microfluidic electroporation assay can evaluate a range of electroporation conditions in a fraction of a second, a process that previously took hours. Results of this work will broaden the scope of bacteria available for applications in genetic engineering and synthetic biology.
Cullen R. Buie is an Assistant Professor of Mechanical Engineering at MIT. He attended The Ohio State University where he received his B.S. in Mechanical Engineering (2003). He attended Stanford University as a National Science Foundation Graduate Research Fellow and obtained his M.S. (2005) and Ph.D. (2009) in Mechanical Engineering. Cullen's Ph.D. research, with Professor Juan Santiago, involved the study of microfluidic pumps to manage liquid water in proton exchange membrane fuel cells. Cullen spent a year at UC Berkeley working with Professor Liwei Lin and Professor John Coates as a UC President’s Postdoctoral Fellow. At MIT his laboratory explores flow physics at the microscale for applications in materials science and microbiology. Cullen is the recipient of numerous awards for his research and service including the National Science Foundation CAREER Award (2012), the DuPont Young Professor Award (2013), and the DARPA Young Faculty Award (2013).