Correlated photons in superresolution imaging and correlated motions in biophysical interaction
Alexander Rohrbach
15 May 2024
12:30
Nexus
Abstract
Our research concentrates on light scattering at small biological structures enabling image formation and particle tracking in biophysics.
Coherent light, i.e. correlated photons enable higher scattering cross-sections than for instance incoherent fluorescence light. Thereby laser light enables to acquire images with millisecond integration times and small motion blur of dynamic particles, such as viruses in the cell periphery. The inherent speckle formation in coherent imaging is avoided by a novel technique called Rotating Coherent Scattering (ROCS) microscopy, which is the only technique that can image diffusing viruses and thereby allows to investigate their binding behavior to the cell periphery.
In the second part of my talk I discuss correlated particle motions, i.e. timescale dependent memory effects in viscoelastic media such as the cell periphery. Using a frequency decomposition of the tracked particle motions, apparently invisible binding of particles to the cell can be made visible.
Short CV
I studied physics at the university of Erlangen-Nürnberg (Germany), where I did my diploma in 1994 at the institute of optics. During my PhD in physics in Heidelberg I investigated different kinds of light scattering at the University, as well as evanescent wave microscopy at the Max-Planck-Institute for medical research. In both cases I worked on applications in cell biology. After my PhD in 1998, I continued my research as a Post-Doc at the European Molecular Biology Laboratory (EMBL) in Heidelberg. I intensified my studies on microscopy, light scattering and optical forces. In 2001 I became project leader of the photonic force microscopy group at EMBL, where I concentrated on the further technical development of this scanning probe microscopy and on applications in biophysics and soft matter physics. In 2005 I was awarded with the habilitation in physics at the university of Heidelberg. Since January 2006 I have been a full professor for Bio- and Nano-Photonics at IMTEK, Faculty of engineering and since 2007 also a member of the physics faculty, University of Freiburg.
I love mathematical models and I hate when the performance of scientists is squeezed into metric numbers.