Abstract

Fluorescence correlation spectroscopy (FCS) is a technique based on the measurement of the spontaneous fluctuations of the fluorescence signal of a small number of molecules. Fluorescence fluctuations are typically measured in an optically restricted sub-micron observation volume, and then analyzed statistically to reveal kinetic information about the processes that lead to these fluctuations. Such processes include concentration fluctuations via molecular diffusion, chemical reactions, photophysical processes, etc. I will present an overview of the technique, and discuss our recent applications of FRET-FCS to the study of conformational dynamics in nucleosomes.