1. Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg D-69120, Germany.
2. AMOLF, Science Park 104, 1098 XG Amsterdam, Netherlands.
3. Department of Bionanoscience, Delft University of Technology and Kavli Institute of Nanoscience Delft, 2629HZ Delft, Netherlands.