1. Department of Electrical and Information Engineering Polytechnic University of Bari Bari 70125 Italy
2. Department of Biomedical Engineering, College of Optical Sciences, and BIO5 Institute University of Arizona Tucson AZ 85721 USA
3. Biomolecular Photonics, Department of Physics University of Bielefeld Bielefeld 33615 Germany
4. Department of Molecular Medicine University of Pavia Pavia 27100 Italy
5. School of Medicine University of Nottingham Nottingham NG7 2RD UK
6. Laboratory of Rare Human Circulating Cells (LCCRH) University Medical Center of Montpellier Montpellier 34093 CEDEX 5 France