Florescence Lifetime – Dependent Flow Cytometry: A New Parameter for Single Cell Sorting and Analysis
Dr. Jessica Houston, Department of Chemical Engineering, New Mexico State University
Monday, Feb. 10, 2014
Biodesign Institute (BDB) 105 [map]
In this seminar time-resolved flow cytometry instrumentation and applications are described with a focus on new developments from the Houston Laboratory of Flow Cytometry and Related Biophotonics. Time-resolved cytometry detection is the ability to measure the fluorescence lifetime of a molecular species at the throughput of standard cytometry. The fluorescence lifetime is the average time a fluorescent molecule spends in its excited state prior to relaxation to the ground state; it is a unique photophysical trait that, with time-resolved detection systems, can provide quantitative information for cellular assays. In the case of biomedical assays using proteins, polymers, fluorophores, chromophores, quantum dots, nanoparticles, and other targets for diagnostics, instruments that provide sensitive relaxation kinetic measurements may help bridge qualitative with quantitative information.
Yet it is well known that to observe an excited state is difficult; radiative decay happens over nearly infinitesimal (e.g., nanoseconds to near-instantaneous) timescales. Moreover, it is non-trivial to capture heterogeneous time-resolved information from several different excitable molecules when excitation is observed from single cells and particles in fluidic states. Therefore, this seminar discusses and summarizes the techniques now being used for high throughput multi-exponential fluorescence decay detection using flow cytometry. Examples include measurements of Förster resonance energy transfer, fluorescence lifetime shifts elicited by autofluorescence species and fluorescent proteins, and the translation of imaging tricks to flow cytometry.
Jessica P. Houston is currently an Assistant Professor in the Department of Chemical Engineering at New Mexico State University. Her research interests include biophotonics, optical imaging, flow cytometry, and fluorescence-lifetime measurements. She began research in the area of photon migration while at Texas A&M University (TAMU) in College Station TX. Houston received her Ph.D. in Chemical Engineering from TAMU in 2005 and later worked at the University of Texas M.D. Anderson Cancer Center, and Baylor College of Medicine. Houston concentrated on developing an expertise in flow cytometry while a Director’s Postdoctoral Fellow from 2006-2009 at Los Alamos National Laboratory (LANL). Since joining New Mexico State University in 2009, she has continued to focus her research on fluorescence-based high-throughput diagnostics to capture excited-state phenomena. She is currently exploring the use and robustness of ‘digital frequency-domain flow cytometry sorting and analysis’ and applications thereof. Some of Houston’s most notable honors are the Outstanding Junior Faculty Award by the Hispanic Faculty and Staff Caucus at NMSU, the Research Achievement Award by the NMSU Vice President for Research Office, and the NSF CAREER award in 2012.