Scientific themes in the Laboratory for Biological Geochemistry are situated at the junction between isotope geochemistry and biology.
We investigate biological processes with global impact at the sub-cellular level using cutting-edge micro-analytical tools. To this end, we use a suite of isotopic labeling techniques in combination with micro- to nano-scale analytical instruments, primarily:
- Secondary electron microscopy (SEM)
- Nanoscale Secondary Ion Mass spectroscopy (NanoSIMS).
The analytical centerpiece of the laboratory is newly developed and unique CryoNanoSIMS ion microprobe. This instrument enables isotopic and elemental imaging with a spatial resolution better than 100 nanometers on a wide range of materials from biological samples, over minerals, to advanced applied materials. In cryo-mode, the CryoNanoSIMS enables highly sensitive mapping of solute distributions and isotope compositions in vitrified biological tissue, i.e., without loss of soluble compounds, which opens an entirely new research frontier.
Among a diverse set of projects in our laboratory, we use these analytical tools to study metabolic interactions between corals and their symbiotic partners, such as microalgae and bacteria, in the context of global warming and acidification. We also attempt to understand, at the cellular level, how corals and other marine organisms (such as foraminifera) form their skeletons and tests through the (poorly understood) process of carbonate biomineralization. On a global scale, such carbonate biomineralization activity creates the structural foundation of immense ecosystems and have major impact on ocean geochemical cycles, second only to primary production.