Dr. Christoph Baumann, Lecturer in Molecular Biophysics
Department of Biology, University of York
Dr. Christoph Baumann, Lecturer at the University of York, Department of Biology and his group work with advanced imaging techniques to push forward our understanding of spatio-temporal dynamics in the bacterial cell envelope. Using a Photometrics camera, the group was the ﬁrst to observe that, contrary to expectations, proteins in the outer cell membrane don’t diffuse signiﬁcantly when tracked, and that new proteins are inserted predominantly at mid-cell during growth.1 This means that bacteria can very quickly turnover their outer membrane proteins to adapt to new environmental challenges during growth, and this work initiated a new investigation of inter-membrane crosstalk in the Gram negative bacterial cell envelope.
To pursue this research area, Dr. Baumann and his colleagues use TIRF microscopy alongside laser scanning confocal FRAP microscopy. When tracking single molecules, sensitivity and speed are all-important. “Better temporal and spatial resolution means better quality data,” Dr. Baumann shares. Previously, the large pixels, slow speed, and the excess noise factor of their EMCCD camera limited both these aspects. Further, the small sensor size and the need to use a 1.6× magniﬁcation optic to match pixel size lead to a very small ﬁeld of view, and using additional lenses lost them precious light.
Better temporal and spatial resolution means better quality data. We’ll definitely be using the Prime 95B Scientific CMOS (sCMOS) camera for our upcoming experiments.
- Supramolecular assemblies underpin turnover of outer membrane proteins in bacteria, P. Rassam et al., 2015, Nature 523: 333-336.
- Intermembrane crosstalk drives inner-membrane protein organization in Escherichia coli, P. Rassam et al., 2018, Nature Commun 9: 1082.