News item: Video-rate STED nanoscopy of living neurons

Göttingen (Germany) – Light microscopy is the most popular imaging method in the biological sciences. In particular, studying dynamics opened up an enormous field of application. Meanwhile the diffraction barrier has been overcome by a number of ‘diffraction-unlimited’ nanoscopy or superresolution techniques, the first of which was Stimulated Emission Depletion (STED) microscopy, invented by the team of Stefan W. Hell. So far, the method has been established on largely static or slowly moving samples only. Now, Hell and his colleagues from the Max Planck Institute for Biophysical Chemistry and the European Neuroscience Institute (Göttingen, Germany) also prove the outstanding performance of video-rate STED microscopy.
In the Topical Issue of the Journal of Biophotonics about „Advanced Micro and Nanoscopy for Biomedicine”, the researchers draw, for the first time, a direct comparison of conventional and high-resolution movies from inside living cells using confocal and pulsed mode STED microscopy. Studying synaptic vesicles within a living axon, a lateral resolution of 65 nm could be observed in STED movies at video rates (28 frames per second), which is 4-fold higher in spatial resolution than in confocal microscopy. Whereas confocal microscopy could only reproduce the axon, the STED movies clearly visualized the motion of single vesicles, revealing specific patterns of movement within the confined space of the axon.
Moreover, the team was able to demonstrate that video-rate STED microscopy can also be performed with continuous wave beams. Continuous wave excitation causes emission to occur continously, allowing for capturing more photons per unit time. This could facilitate extending fast STED imaging towards imaging fainter living samples.

J. Biophotonics, Volume 3, Issue 7 (p 417-424); DOI 10.1002/jbio.201000038