Cell structure analysis using optical nanoscopy

The optical analysis of structures in mammal cells, in particular in human cancer cells, is essentiell for a mechanistic understanding of the cell answer to DNA damages and cell communication.

Conventional optical epifluorescence microscopy has only limited usability for these analyses due to its diffraction limitation and its maximum resolution of approx. 250 nm. This fundamental limit has already been described in the 19th century be Ernst Abbe. Modern microscopy methods have found ways to circumvent this limitation and to reach resolutions of 100 nm to only a few nanometer.

The commercial Leica TCS SP8 3X STED (stimulated emission depletion) microscope installed at the LRT2 institute uses the spatial overlay of excitation laser and the doughnut-shaped de-excitation laser to improve resolution below 100 nm. For the invention of this microscopy method, Stefan W. Hell was awarded the Nobel prize in 2014.

On the one hand, the STED microscope offers the possibility to analyze the clustering of repair proteins to DNA double-strand breaks with increased resolution and thus to study the interactions between various proteins and with the DNA.

On the other hand, the additionally installed climate chamber enables the study of living cells. This involves the analysis of network formation among different cells, cell-cell-communication as well as the study of structural changes of the cell organelles.

We offer the use of our STED microscope for studies on fixated as well as living cells to potential users in the field of radio- and cell biology. Access is provided to the biolab, including equipment, the cell cultures and biological protocols. The user support staff are experienced in developing new protocols as required, and in implementing and performing these protocols in collaboration with the external users. Furthermore, there is the option of performing nanoscopic studies in combination with radiobiological experiments at the ion microprobe SNAKE.