University Medical Center Freiburg 3 articles published in JoVE Medicine Electromechanical Assessment of Optogenetically Modulated Cardiomyocyte Activity Ramona A. Kopton1,2,3, Cinthia Buchmann1,2, Robin Moss1,2, Peter Kohl1,2, Rémi Peyronnet1,2, Franziska Schneider-Warme1,2 1Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Medical Center-University of Freiburg, 2Faculty of Medicine, University of Freiburg, 3Faculty of Biology, University of Freiburg We present a protocol for evaluating the electromechanical effects of GtACR1 activation in rabbit cardiomyocytes. We provide detailed information on cell isolation, culturing and adenoviral transduction, and on functional experiments with the patch-clamp and carbon-fiber techniques. Cancer Research Cell Cycle-specific Measurement of γH2AX and Apoptosis After Genotoxic Stress by Flow Cytometry Ramon Lopez Perez1,2, Franziska Münz1,2, Jonas Kroschke1,2, Jannek Brauer1,2, Nils H. Nicolay1,2,3, Peter E. Huber1,2 1CCU Molecular and Radiation Oncology, German Cancer Research Center, 2Department of Radiation Oncology, Heidelberg University Hospital, 3Department of Radiation Oncology, Freiburg University Medical Center The presented method combines the quantitative analysis of DNA double-strand breaks (DSBs), cell cycle distribution and apoptosis to enable cell cycle-specific evaluation of DSB induction and repair as well as the consequences of repair failure. Genetics Constitutive and Inducible Systems for Genetic In Vivo Modification of Mouse Hepatocytes Using Hydrodynamic Tail Vein Injection Eric K. Hubner1,2, Christian Lechler1, Thomas N. Rösner1, Birgit Kohnke-Ertel1, Roland M. Schmid1, Ursula Ehmer1 1Department of Medicine II, Klinikum rechts der Isar, Technische Universität München, 2Department of Pneumology, Center for Medicine, Medical Center University of Freiburg Hydrodynamic tail vein injection of transposon-based integration vectors enables stable transfection of murine hepatocytes in vivo. Here, we present a practical protocol for transfection systems that enables the long-term constitutive expression of a single transgene or combined constitutive and doxycycline-inducible expression of a transgene or miR-shRNA in the liver.