Multi-colour live-cell STED Microscope

• Subject Area: Basic Research in Biology and Medicine
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 553898587

We apply for funding to acquire a multi-color stimulated emission depletion (STED) microscope. This advanced instrument will empower researchers to perform multi-target microscopy experiments in living cells and tissues at sub-diffraction resolution, addressing a significant gap in our current bioimaging capabilities at the Goethe-University Frankfurt. Super-resolution microscopy has revolutionised cell biology by providing a molecular perspective on the emergence, function, and decay of cellular structures. The demand for deeper insights into molecular interactions, protein dynamics, and subcellular distributions within living cells and tissues is ever-growing. STED nanoscopy, pioneered by Nobel laureate Prof. Dr. Stefan W. Hell, has become indispensable in biological research. It offers crucial insights into organelles, cells, and tissues by enabling instant super-resolution imaging without the need for mathematical image reconstruction. With a practical spatial resolution of down to ~30 nm, STED nanoscopy outperforms live-cell compatible extended-resolution techniques like structured illumination microscopy (SIM) or image scanning microscopy (ISM, "Airy Scan") that are currently available at GU. However, cutting-edge super-resolution techniques such as STED nanoscopy impose higher light doses on the samples and are slower compared to diffraction-limited imaging. Advancements in optical components and data processing have addressed these drawbacks, enabling rapid yet gentle STED imaging of live specimens with sub-diffraction spatial resolution. Optimizing imaging speed and reducing light doses are especially important for capturing rapid cellular dynamics for a prolonged time. The proposed STED microscope meets these requirements, integrating state-of-the-art technical solutions to reduce phototoxic effects. It features tuneable excitation wavelengths, spectral detection and a fast scanner to ensure rapid, photon-efficient multiplexing. Time-resolved single-photon-sensitive detectors enable lifetime STED imaging, further reducing the photon burden on live specimens. Moreover, lifetime detection allows the simultaneous detection of multiple spectrally similar fluorophores using a single depletion wavelength, simplifying multiplexed analysis. In conclusion, the proposed multi-colour live-cell STED microscope, equipped with a tuneable white light laser source, two STED depletion lasers, flexible spectral detection, lifetime detection, and a fast resonant scanner, will provide GU researchers with unparalleled capabilities for studying cells and tissues at nanoscale resolution. This STED microscope will not only benefit the intended research groups but also foster collaborative efforts and advance the understanding of fundamental cellular processes, making it an invaluable resource for the scientific community at GU.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Multifarben-Lebendzell-STED-Mikroskop
• Instrumentation Group: 5090 Spezialmikroskope
• Applicant Institution: Goethe-Universität Frankfurt am Main
• Leader: Professor Dr. Mike Heilemann