Live-cell nanoscale imaging system based on fluorescence lifetime

The requested fluorescence lifetime–based confocal and super-resolution microscope will enable research groups at the Institute of Biology to study molecular interactions and dynamics in living cells at the nanoscale. Many essential biological processes, including synaptic plasticity, chromatin reorganization, organelle transport, and cytoskeletal remodelling, occur below the diffraction limit of conventional light microscopy and therefore remain poorly accessible. Super-resolution microscopy has transformed cell biology, and among existing techniques, stimulated emission depletion (STED) microscopy is the best adapted to multicolour live-cell imaging. The most advanced implementation, lifetime-STED (LT-STED), utilizes fluorescence lifetime information to achieve outstanding spatial resolution with high temporal performance and minimal light exposure, thereby enabling long-term imaging of sensitive samples, such as neurons or plant cells. Combining a state-of-the-art confocal platform equipped with a white-light laser and lifetime detectors, the system will support both gentle super-resolution imaging and advanced multiplexing. This will open new possibilities for analysing signalling pathways, organelle communication, and protein dynamics in living cells and tissues. The LT-STED/confocal microscope will significantly enhance the imaging infrastructure at the Humboldt-Universität zu Berlin (HU), foster interdisciplinary research, and provide cutting-edge training for early-career scientists. Several research projects critically depend on this system and cannot be realised with existing infrastructure. AG Mikhaylova will study cytoskeleton–synapse interactions in mammalian neurons, including microtubule organisation, synaptic maintenance, and alterations in SHANK3-linked autism models, as well as the role of autophagosomal and lysosomal pathways. LT-STED will enable live, volumetric nanoscale imaging, while fluorescence lifetime microscopy (FLIM) will assess the functional state of degradative compartments. AG Plested will apply multicolour LT-STED to resolve synaptic nanostructure and glutamate receptor organisation, combined with FLIM-FRET (Förster resonance energy transfer) to analyse receptor dynamics. AG Kaufmann will use 3D multiplex imaging to investigate transcription factor mobility, chromatin architecture, and gene regulation during flower development and environmental adaptation. Overall, the system will strengthen cross-disciplinary collaboration and position the HU as a leading centre for advanced imaging research.