Laser microscope for investigating the elasticity of cells using the stimulated scattering of acoustic and optical waves
The mechanical properties of biological cells are closely related with their functional capabilities. Hence, they are considered to play a key role in the understanding of a variety of fundamental aspects in biology and of the origin of diseases. Moreover, mechanical properties like elasticity are effective markers for diseases, which can provide powerful diagnostics e.g. for oncology. Atomic force microscopes are able to determine elasticity with subcellular spatial resolution, but they require a direct contact to and preparation of the sample. To overcome these limitations, a paradigm shift from tactile techniques to optical methods is pursued. Brillouin scattering, based on the interaction of acoustical phonons and photons, allows for contact-free, label-free and three-dimensional in-vivo measurements of the elasticity. So far, measurements were based on spontaneous Brillouin scattering, which exhibits only a poor signal-to-noise ratio (SNR) and hence requires long averaging times.
Within the funding program “New Instrumentation for Research”, a laser microscope based on the evaluation of stimulated Brillouin scattering is realized, whereby the SNR and the measurement speed can be increased by several orders of magnitude.
The aim of the highly interdisciplinary approach lies in the setup, the investigation and validation of a stimulated Brillouin laser microscope with methods from laser metrology and systems engineering as well as the realization of a demonstrator for the later use in biology and medicine. The validation of the measurement principle will be performed by reference measurements of the biomechanics. New possibilities for research concerning spatio-temporal correlations of the elasticity of cells will be investigated employing flow cytometry.
The novel stimulated Brillouin laser microscope for subcellular investigations of elasticity as a contact-free measurement approach opens a broad spectrum of applications in medicine, ranging from biomechanical imaging of cells to fundamental questions concerning the physics of life.
Symbolic image "feeling with light" © Benedikt Krug
Intersection of the excitation beams in the sample © Benedikt Krug
Staff: B. Krug, N. Koukourakis, J. Czarske
Period: 04/19 - 03/22
Partner: BIOTEC, Dresden, Prof. Jochen Guck