Raman-Based Analysis of Natural Products in Complex Biosystems
In project Z02 the almost complete value chain of Raman-based approaches including Raman microscopy, resonance Raman (micro)spectroscopy, surface enhanced Raman spectroscopy (SERS) or coherent anti-Stokes Raman (CARS) microscopy offered by the laboratories run by the PI J. Popp will be provided to specific A, B and C projects. These techniques offer the unique opportunity to monitor the spatial distribution of specific metabolites in complex systems, thereby enabling the visualization of chemical gradients in a dynamic way. We were able to show within the last years that these Raman approaches are powerful tools to address a broad spectrum of biomedical and life sciences questions (see project related publications). Raman technologies are highly specific since they provide a molecular fingerprint of the sample. Furthermore, Raman spectroscopy offers minimal sample preparation and does not require external labels in contrast to fluorescence microscopy. While the advantages of Raman spectroscopy are its unprecedented high specificity and its versatility it suffers from poor sensitivity limiting the detection of biomolecules being present in very low concentrations. This disadvantage can be partially overcome by utilizing special Raman signal enhancing techniques like e.g. resonance Raman spectroscopy, surface enhanced Raman scattering (SERS) or by non-linear Raman phenomena like CARS = coherent anti-Stokes Raman scattering that are offered to the consortium.
While the project Z02 which is in general dedicated to Raman-based microspectroscopy provided as central service to the CRC is open for all projects. A special focus will be on joint approaches together with the MALDI imaging activities of B01 several involvements in specific projects are already planned, e.g. A01: Raman and CARS spectroscopic imaging of macroalgae surfaces to monitor changes in the surface chemistry due to morphogenesis; A04: Raman and CARS imaging of tumor cells in the context of monocytes/macrophages; B03: Raman and CARS imaging of gut microbial communities of insects; B04: Raman spectroscopic analysis and monitoring of the release of active agents out of polymer capsules both in-vitro and in an ecological context that is e.g. within insect guts; C02: Raman spectroscopic analysis of plant surfaces, B06 & C04,C05: Raman and resonance Raman spectroscopic characterization of (photoreactive) Fe(III) ligands and further metallophores involved in metal recruitment by nitrogen fixing bacteria. PhD and postdoctoral researchers will be given the opportunity to investigate their system in close interaction with advanced researchers and technicians. Thereby the expertise with the respective system will be brought into an environment devoted to elaborate analytical approaches – a concept that proved already to be very fruitful for the observation of even complex systems in numerous projects.