Osnabruck University 3 articles published in JoVE Biology Multi-color Localization Microscopy of Single Membrane Proteins in Organelles of Live Mammalian Cells Timo Appelhans1, Felix R.M. Beinlich1, Christian P. Richter1, Rainer Kurre2, Karin B. Busch1,3 1School of Biology, University of Osnabrück, 2Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, 3Department of Biology, WWU Münster Here, we present a protocol for multi-color localization of single membrane proteins in organelles of live cells. To attach fluorophores, self-labeling proteins are used. Proteins, located in different membranes compartments of the same organelle, can be localized with a precision of ~18 nm. Immunology and Infection Application of Fluorescent Nanoparticles to Study Remodeling of the Endo-lysosomal System by Intracellular Bacteria Yuying Zhang1, Viktoria Krieger1, Michael Hensel1 1Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück This article describes methods for the synthesis and fluorescent labeling of nanoparticles (NPs). The NPs were applied in pulse-chase experiments to label the endo-lysosomal system of eukaryotic cells. Manipulation of the endo-lysosomal system by activities of the intracellular pathogen Salmonella enterica were followed by live cell imaging and quantified. Bioengineering Membrane-SPINE: A Biochemical Tool to Identify Protein-protein Interactions of Membrane Proteins In Vivo Volker Steffen Müller1, Karolin Tschauner1, Sabine Hunke1 1Molekulare Mikrobiologie, Universität Osnabrück A biochemical approach is described to identify in vivo protein-protein interactions (PPI) of membrane proteins. The method combines protein cross-linking, affinity purification and mass spectrometry, and is adaptable to almost any cell type or organism. With this approach, even the identification of transient PPIs becomes possible.