The present invention relates to a method for testing a substance interacting with a target molecule in a cell by fluorescence correlation spectroscopy (FCS) by adding a test substance to the cell and determining a distribution of diffusion coefficients for the fluorescently labelled target molecule. Preferably, the target molecule is a nuclear hormone receptor, e.g. the estrogen receptor.
Cathrin Brisken, Giovanna Ambrosini, Georgios Sflomos, Yueyun Zhang, Hazel Margaret Quinn, Kelly Spry Maggs, Patrik Aouad, Fabio De Martino, Céline Marie Victoria Stibolt