Department of Physics & Astronomy
University of New Mexico

OSE Seminars

Imaging Cellular Components and Dynamics with Sub-Diffraction Resolution

Presented by Professor Keith Lidke, UNM Physics and Astronomy

Due to the near transparency of cells, optical imaging is well suited for studying live or intact cells. Tagging cellular components with fluorophores dramatically extends these capabilities by providing molecular specificity and improved contrast. However, the light microscope is limited by diffraction to ~ 300 nm, whereas many important events for cell function and signaling involve interactions of proteins that occur at the ~ 10 nm scale. I will discuss methods for circumventing the diffraction limit using single molecule fluorescence imaging with a focus on technical development and remaining issues.

The imaging of a single florescent molecule allows the localization of the fluorophore with a precision limited by the number of collected photons, and in practice is ~ 10 nm. Sequential imaging and localization of individual fluorescent tags in a sample can be used for reconstructing super-resolution images. Single particle tracking techniques using quantum dots and other bright fluorescence probes provide single particle localizations with a precision well below the diffraction limit, however, clustering of multiple particles limits the unique identification and thus tracking of individual particles throughout the (possibly dynamic) clustering process. I will describe multi-color tracking as well as our unique high-speed hyperspectral microscope that allows the capability to track membrane proteins at densities up to 10 proteins per square micron at 30 Hz. I will also discuss the challenges in extracting information from these large, multi-dimensional data sets.

11:00 am, Thursday, March 2, 2017
Room 103, Center for High Tech Materials
Science and Technology Park - South Campus

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A schedule of talks within the Department of Physics and Astronomy is available on the P&A web site at http://physics.unm.edu/pandaweb/events/index.php