Regensburg 2016 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 8: Bioimaging and Spectroscopy I

BP 8.2: Vortrag

Montag, 7. März 2016, 12:00–12:15, H43

Label-free high contrast superresolution microscopy at 100Hz using coherent dark field illumination in TIR mode (TIR-CODAF) — •Dominic Ruh, Felix Jünger, Philipp von Olshausen, and Alexander Rohrbach — University of Freiburg, Department of Microsystems Engineering - IMTEK, Laboratory for Bio- and Nano-Photonics, Germany

Cells are the smallest units of life. A variety of forces constantly act on these complex systems, pushing them out of equilibrium and causing a manifold of signaling events. The investigation of fast dynamic processes in living cells resulting from these forces require fast measurement techniques - faster and more precise than currently available. The technique presented in this work uses a laser beam that illuminates a living, unlabeled cell under an oblique angle. The monochromatic light is multiply scattered at the cellular structures yielding an image of the cell on the camera that is strongly distorted by speckles. However, by sweeping the laser beam along a circular path in the back focal plane of the objective lens during the integration time of the camera (e.g. only some milliseconds), the speckles cancel out and a high contrast image of the cell is obtained. We call this new technique *total internal reflection coherent dark field (TIR-CODAF) microscopy*. In this talk we present a resolution of 150 nm at a frame rate of 100 Hz. Since TIR-CODAF does not rely on fluorescence many thousands of images without visible loss of image quality can be acquired.