Regensburg 2022 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

BP: Fachverband Biologische Physik

BP 7: Poster 1

BP 7.45: Poster

Monday, September 5, 2022, 18:00–20:00, P1

Absorption-based specificity in ROCS microscopy — •Victor Chuman and Alexander Rohrbach — University of Freiburg, Department of Microsystems Engineering - IMTEK, Laboratory for Bio- and Nano-Photonics, Georges-Köhler-Allee 102, 79110 Freiburg, Germany

Fluorescence techniques dominate the field of live-cell microscopy, but bleaching and motion blur from too long integration times limit dynamic investigations of small objects. High contrast, label-free life-cell imaging of thousands of acquisitions at 150nm and 200 Hz is possible by Rotating Coherent Scattering (ROCS) microscopy, where intensity speckle patterns from all azimuthal illumination directions are added up within a few milliseconds. However, ROCS lacks the important imaging feature of specificity. We address this deficiency by using different absorption markers, characterized by their different complex valued refractive indices to achieve a difference in image contrast in the observed structures. We demonstrate how different gray values in the image are obtained from interferences between scattered and unscattered light, resulting from material dependent phase shifts of the scattered light. Absorption-based specificity in ROCS imaging may open new fields of applications, adding on top of its high spatio-temporal resolution.