Stimulated Emission Depletion microscopy

The STED microscope (Stimulated Emission Depletion) enables selectively depletion of the fluorophores on the outpart of the focal point (see fig), which greatly reduce the volume where fluorescence can be emitted, and so provide a resolution of ten nanometers. This technique developed by Stefan Hell team is slowing spreading in the community as the technical implementation tends to be tedious.

In collaboration with CPBM and the group of ELSA from Intsitut d’optique, we have developed a system offering tunability fro excitation/depletion beam, associated with dynamic detection (FLIM / FCS). Our device built up by Siddharth Sivankutty during is thesis currently can achieve a lateral resolution of about 40 nm, as illustrated in fluorescent nanospheres images and the associated profile (see fig. below). Experiments on actin network allow to highlight that the gain in resolution is preserved in cell.