1. Nanobiophysics (NBP), MESA+ Institute for Nanotechnology and Technical Medical Centre, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AEEnschede, The Netherlands
2. Section of Molecular Cytology, Swammerdam Institute for Life Sciences, University of Amsterdam, P.O. Box 94215, 1090 GEAmsterdam, The Netherlands