|
Optical Spectroscopy Section
Jay R Knutson, PhD, Principal Investigator
The Optical Spectroscopy Section develops and exploits ultrafast laser – based instrumentation to study
the structure and dynamics of proteins, DNA and their assemblies in solution and in cells and/or tissues.
We specialize in time-resolved fluorescence, but we employ other (absorption, coherent vibrational)
techniques as needed. At present, we do picosecond fluorescent lifetime and anisotropy studies via both
TCSPC (time-correlated single photon counting) and phase fluorometry, to learn about the size, shape and
flexibility of assemblies. We exploit the “self-strobing” of a laser to study protein water coats that move
in a few hundred femtoseconds (light travels about 186,000 miles/second, so light moves about a foot per
nanosecond and a hundred femtoseconds is about the time it takes light to cross a human hair). We also employ
2-photon microscopy to do fluorescence lifetime imaging in cells; we study the Brownian motion of
macromolecules with a two-photon two-color fluorescence cross-correlation spectroscopy instrument (TPTCFCCS)
that , e.g., traces the binding of proteins within cell nuclei, and we are building a CARS microscope
(a 3-photon technique that makes nonfluorescent molecules glow with a “fingerprint” color matched to the
internal bond strength). Novel microscopes that explore conformation fluctuation and imaging of fluorescence
down to protein size scales are also in construction.
|
<%
section = Request.ServerVariables("PATH_INFO")
%>
