Beating the Diffraction Limit
2014 R&D 100 Winner
Super-resolution microscopy has emerged as a leading subcellular imaging technique over the past decade, bringing tagged nanoscopic biological elements into full view for researchers. Leica Microsystems has been a development leader in this segment of microscopy, and one of its newest products, the TCS SP8 STED 3X, brings a new element to imaging capabilities. Unlike prior systems, which restrict optical resolution improvements to the lateral direction only, the new system extends improvements into the axial direction, making true 3-D super-resolution possible for the first time.
Based on the concept of stimulated emission depletion technology (STED) developed by Stefan Hell at Max Planck Institute, the TCS SP8 STED 3X uses superimposed lasers to reduce the effective focal spot scanning the specimen to an area smaller than the diffraction limit. For best resolution in x and y the light is allocated to the STED pathway, which creates the established STED “donut”-shaped laser spot by a vortex phase mask. The resulting effective focal volume is rod-shaped. A second light path with a different phase mask forms a z “donut”, yielding resolution increases mainly in z but also in x and y. With a newly available 775 nm-STED laser, Leica’s 3X achieves a resolution below 30 nm.
3-D superresolution microscope
|Leica Microsystems' TCS SP8 STED 3X development team. Front row (l-r): Janine Pazdyka, Daniella Kern, Jochen Sieber, Arnold Giske, Andreas Schneider and Jan Schroder. Back row (l-r): Barbara Pfeifer, Wernher Fouquet, Lars Friedrich, Heidi Braun, Roland Seifert, Marius Lange, Jochen Pruess and Alexander Petri.|
The TCS SP8 STED 3X Development Team
Arnold Giske, Principal Developer, Leica Microsystems CMS GmbH
Stefan W. Hell, Principal Developer, Max Planck Institute for Biophysical Chemistry
Jochen Sieber, Principal Developer, Leica Microsystems CMS GmbH