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BP: Fachverband Biologische Physik

BP 25: Membranes

BP 25.2: Vortrag

Freitag, 27. März 2009, 10:45–11:00, HÜL 186

Multi-Parameter Analysis of Inter-Membrane Adhesion Using Simultaneous Fluorescence and Reflection Interference Contrast Microscopy (RICM) — •Susanne Fenz¹, Rudolph Merkel¹, and Kheya Sengupta² — ¹Institute of Bio- and Nanosystems (IBN), Research Centre Jülich, 52425 Jülich, Germany — ²Centre Interdisciplinaire de Nanosciences de Marseille (CINAM/CNRS-UPR3118), Luminy, Marseille Cedex 9, France

We present a biomimetic model system for cell-cell adhesion consisting of a giant unilamellar vesicle (GUV) adhering via specific biotin-neutravidin interaction to a supported lipid bilayer (SLB). Based on a standard fluorescence microscope, a new set-up was developed that enables simultaneous imaging in RICM and fluorescence microscopy as well as determination of molecular diffusion by continuous photobleaching. GUVs adhering to SLBs were characterized with respect to their inter-membrane distance, adhesion energy density and fluctuation amplitude. Fluorescent imaging and recovery after photobleaching of receptors yielded their distribution, concentration and diffusion constant. We present both static and dynamic analysis of the inter-membrane distance and bond ordering for the limiting cases of dense and dilute bonds.