Confocal laser scanning microscope

• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 554545121

Our interdisciplinary research activities at the intersection of physics, nanotechnology and biology require a confocal laser scanning fluorescence microscope capable of multicolour in-situ imaging over a broad spectral range with highest spatial resolution and sensitivity operated at elevated speeds. The 2. Physics Institute (leading applicant) with research focus on DNA-nanotechnology and cellular biomimicry, will predominantly employ multicolour confocal microscopy and related techniques such as advanced variations of fluorescence correlation spectroscopy (FCS), fluorescence recovery after photobleaching (FRAP) and Förster resonance energy transfer (FRET) to characterize the structeural properties, dynamical functionalities and kinetics of DNA-based nanostructures and cell mimics. Our cell mimics are typically composed of DNA-origami nanostructures and small, large and giant unilamellar vesicles (SUV, LUV, GUV) that can be easily labelled with nearly freely selectable fluorescent dyes. Dynamical functionalities and kinetics of interest include the formation of mimics and complex DNA-origami assemblies, diffusion of DNA-origami (assemblies) and SUVs on lipid membranes, (directed) cargo transport on and through membranes or cell mimics, mechanical stress induced deformation of cell mimics as well as mechanical motions of DNA-based nanostructures (rotation, sliding etc.). Members of the biophysics group at the Institute of Biomaterials and Biomolecular Systems (IBBS) will utilize multicolour high-resolution confocal microscopy to explore the process of translocase of the outer membrane (TOM)-mediated protein translocation. In particular FRET, FRAP, advanced FCS and FCCS will be used to investigate the formation, binding and incorporation of TOM transmembrane protein channels in the membrane and their dynamic functionality, e.g. regulation and stress induced transport through the membranes. In-situ multicolour imaging of our samples requires highest lateral resolution with an excellent signal-to-noise-ration (SNR) (to resolve the DNA-origamis, unilamellar vesicles and cell mimics labelled with a few fluorophores only), FRET, FRAP, advanced FCS and FCCS (to investigate the structural configuration and diffusion properties), a broad spectral range (to include a large number of fluorophores to label different elementary building blocks) and fast acquisition speeds (to resolve nanoscale motions and reduce the measurement time for multicolour 3D stacks or time series). A confocal laser scanning microscope combining these versatile functionalities in a single instrument is currently not available at the University of Stuttgart. We therefore heavily rely on the acquisition of such a versatile tool to gain new insight into structural and functional properties of our DNA-based nanoarchitectures and cell mimics as well as the transport processes across biological membranes.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Konfokales-Laser-Scanning-Mikroskop
• Instrumentation Group: 5090 Spezialmikroskope
• Applicant Institution: Universität Stuttgart
• Leader: Professorin Dr. Laura Na Liu