Masters Thesis Defense

Department of Physics

Photo- and Bio-Physical Characterization of Novel Lipophilic Fluorescent Dyes
For Multicolor Neurotracing and Transcellular Lipid Diusion Measurements

by
Jeffrey Tonniges

Abstract:

Lipophilic Fluorescent dyes are used to trace neuronal connections and probe cellular activities by insertion into and lateral diusion within cell membranes. The photophysical and biophysical properties of two sets of lipophilic Fluorescent dyes were characterized to study: 1) how to increase the number of distinct colors in a single specimen for neurotracing, and 2) how the hydrocarbon chain length aects the mechanism for lipid diusion in living cells. To address these inquiries, fluorescence spectroscopy measurements of a multicolored dye set and diusion measurements in cultured cells of a set of dyes with various hydrocarbon chain lengths were performed. Two-photon excitation action cross sections for the multicolored dye set and their use in designing multicolor imaging protocols will be discussed. Transcellular diusion and FRAP measurements of the chain-variant dye set will be presented and the role of the hydrocarbon chain length on lipid diusion will be explored.

Faculty, students, and the general public are invited.
Advisor: Professor Michael Nichols