1. Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
2. Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, U.K.
3. Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, U.K.
4. Molecular Biophysics and Integrated Bio-imaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, U.S.A