1. Federal Institute for Materials Research and Testing, D-12205 Berlin, Germany
2. Department
of Physics, Free University Berlin, D-14195 Berlin, Germany
3. Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytic and Bioprocesses, D-14476 Potsdam-Golm, Germany
4. Institute
of Biochemistry and Biology, University of Potsdam, D-14476 Potsdam, Germany
5. Institute
for Computational Physics, University of Stuttgart, D-70569 Stuttgart, Germany
6. Technical University Berlin, D-10587 Berlin, Germany