1. Biomolecular Mass Spectrometry
Unit, Leiden University Medical Center,
P.O. Box 9600, 2300 RC Leiden, The Netherlands
2. Leiden Institute of Physics,
Huygens Laboratory, Leiden University,
Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
3. CEA, Institut de Biologie et de Technologies de Saclay, 91191 Gif-sur-Yvette,
France