Fluorescence Correlation Spectroscopy

Idea: In this lab course we learn how to use fluorescence correlation spectroscopy (FCS)
to investigate the dynamics of biomolecules

Biophysics Lab Course, Institute of Biophysics, Ulm University


A confocal setup allows detection of fluorescence signals from very small volumes (~ femtoliter).

Diffusion of single fluorescent molecules through this volume, but also intramolecular dynamics lead to fluorescence intensity fluctuations, which can be quantified using autocorrelation analysis.

Here, the diffusion of labelled oligonucleotides is studied in presence of complementary DNA in order to determine the binding affinity, utilizing the reduced mobility of the bound complex.