Advanced confocal laser scan system for imaging fixed and living biological samples

• Subject Area: Microbiology, Virology and Immunology
• Term: Funded in 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 496964877

We apply for an advanced confocal laser scanning microscope with enhanced excitation and detection capabilities. The applied-for microscope will be essential for increasing the imaging quality and capacity available to the researchers working at the University Medical Center Hamburg. The constantly increasing demand for confocal microscopy at the UKE is now exceeding the supply. In the last years, in some critical time periods, we registered extremely long waiting times for booking confocal high resolution imaging sections and a massive usage of late night and weekend sections. We also experienced critical moments when one of the confocal microscopes of the UKE Microscopy Imaging Facility (UMIF) was not available due to repairs, as this interfered with the revision of several high-class papers. Indeed, failures are increasingly likely happen to heavily used successively obsolete microscopes, with repair times lasting between one and three weeks. Due to all these reasons, without a strong increase in available imaging slots, UKE researchers will be tempted to find alternatives to the imaging facility and probably start major instrumentation proposals on their own. This would result in a suboptimal distribution of the imaging resources. Since the applied-for microscope will be used in the local imaging facility, its configuration has to be versatile, and the overall set up should be upgradable. In this way, we can warrant that, for its entire life span, this microscope will be fully used, since it can also be employed for imaging projects that are not listed in this application. Specifically, this microscope should be able to produce high resolution pictures, up to 2 times better than lens diffraction limited resolution, of fixed and living samples. Importantly, this imaging platform should also provide an optimal combination of imaging speed and optical resolution in order to permit to visualize and follow sub-cellular structures in living samples. These requirements can be fulfilled by a confocal microscope that is equipped with better technological solutions in term of optics (objective lenses), excitation sources (lasers) and detectors (enhanced PMTs, GaAsP detectors as well as advanced detector arrays). Finally, the applied-for microscope has to be a versatile platform for imaging a wide range of fixed and living biological samples as, including immune cells such as macrophages or microglial cells, cells infected by a variety of bacteria such as Borrelia burgdorferi, complex models such as canaliculi, three dimensional tumour models, or organoids, and intracellular structures such as actin filaments, microtubules, endoplasmic reticulum, or organelles such as podosomes and phagosomes.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Konfokales Laser Scanning Mikroskop für fixierte und lebende biologische Proben
• Instrumentation Group: 5090 Spezialmikroskope
• Applicant Institution: Universität Hamburg
• Leader: Professor Dr. Stefan Linder