title: Fast, label-free super-resolution live-cell imaging using rotating coherent scattering (ROCS) microscopy.
abstract: Living cells are highly dynamic systems with cellular structures being often below the optical resolution limit. Super-resolution microscopes, usually based on fluorescence cell labelling, are usually too slow to resolve small, dynamic structures. We present a label-free microscopy technique, which can generate thousands of super-resolved, high contrast images at a frame rate of 100 Hertz and without any post-processing. The technique is based on oblique sample illumination with coherent light, an approach believed to be not applicable in life sciences because of too many interference artefacts. However, by circulating an incident laser beam by 360° during one image acquisition, relevant image information is amplified. By combining total internal reflection illumination with dark-field detection, structures as small as 150 nm become separable through local destructive interferences. The technique images local changes in refractive index through scattered laser light and is applied to living mouse macrophages and helical bacteria revealing unexpected dynamic processes.
authors.affiliation: Laboratory for Bio- and Nano-Photonics, Department of Microsystems Engineering, University of Freiburg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Jünger
authors.affiliation: Laboratory for Bio- and Nano-Photonics, Department of Microsystems Engineering, University of Freiburg, Germany.|Testo AG, Testo-Straße 1, 79853 Lenzkirch, Germany.
authors.forename: Philipp V
authors.initials: PV
authors.lastname: Olshausen
authors.affiliation: Laboratory for Bio- and Nano-Photonics, Department of Microsystems Engineering, University of Freiburg, Germany.|BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rohrbach
mesh_terms: D000465:Algorithms; D000818:Animals; D058948:Cell Tracking / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods*