Post-docs and students Details: Benedict Hebert, Ph.D. Student
Benedict Hebert is currently developing and characterizing an extension of Image Correlation Spectroscopy (ICS) that can give directional information (a velocity vector) for fluorescently labeled proteins in vivo. This technique, termed Spatio-Temporal Image Correlation Spectroscopy (STICS), looks at the temporal persistence of spatially correlated intensity fluctuations in order to extract the directional information. Along with this technique, Ben has developed new filtering algorithms to get rid of the dominant immobile population in living cells, and look only at the mobile fraction. Initial applications of the technique include velocity mapping in CHO, MEF and fibroblast cells where adhesion related proteins have been tagged with visible fluorescent proteins (VFPs) to look at the variation of the flow speed and direction under different conditions. The method is also being applied to look at fluid flow of quantum dots in keratocytes. The following picture represents the retrograde flow as calculated by STICS velocity mapping in an expanding protrusion of a CHO cell, where the adhesion related protein alpha-actinin has been labeled with green fluorescent protein (GFP):
RECENT PUBLICATIONS
Bachir, A.I., Durisic, N., Hebert, B., Grütter, P.H. & Wiseman, P.W. Image Correlation Spectroscopy Studies of Blinking Dynamics in Semiconductor Quantum Dots. Appl. Phys. Lett. In press.
Hebert B., Hulme S.E. & Wiseman P.W. (2005) Membrane protein dynamics measured by two-photon ring correlation spectroscopy: theory and application to living cells. Proceedings of SPIE 5700:109-117 (Invited Paper).
Hebert B., Costantino S. & Wiseman P.W. (2005) Spatio temporal image correlation spectroscopy (STICS): Theory, verification and application to protein velocity mapping in living CHO cells. Biophys J. 88:3601-3614
Wiseman P.W., Brown C.M., Webb D.J., Hebert B., Johnson N.L., Squier J.A., Ellisman M.H. & Horwitz A.R. (2004) Spatial mapping of integrin interaction and dynamics during cell migration by image correlation microscopy. J. Cell Science 117: 5521-5534 (Cover article)
MEETINGS
Hebert, B., Wiseman, P.W. (2005) Velocity mapping in living cells: an image correlation study 49th annual meeting of the Biophysical. Society, Long Beach, CA.
Hebert, B., Hulme, S.E., Wiseman, P.W. (2005) Membrane protein dynamics measured by two-photon ring correlation spectroscopy: theory and application to living cells. BIOS Photonics West 2005, San Jose, CA.
Hebert, B., Durisic, N., Bachir, A.I., Costantino, S., Wiseman, P.W. (2004) Emerging optical microscopy methods for in situ cellular measurements of macromolecular dynamics and interactions. International E-Coli Alliance Meeting on Systems Biology, Banff, AB.
Hebert, B., Wiseman, P.W. (2004) Mapping Adhesion Protein Transport and Interactions in Living Cells by Image Correlation Methods. American Society for Photobiology Annual Meeting, Seattle, WA.
Hebert, B., Wiseman, P.W. (2004) Mapping protein interactions, diffusion and flux in living cells by image correlation spectroscopy. Cross Border Workshop on Laser Science. National Research Council, Ottawa, ON.
Hebert, B., Wiseman, P.W. (2004) Velocity mapping of integrins in living CHO cells: an image correlation study. 48th Annual Meeting of the Biophysical Society, Baltimore, MD.
Hebert, B., Wiseman, P.W. (2004) Velocity mapping of protein fluxes in living cells by space-time image correlation. BIOS Photonics West 2004 conference, San Jose, CA. |
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