1. D. T. Chiu, S. J. Lillard, R. N. Zare, Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
2. R. H. Scheller, Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
3. S. E. Rodriguez-Cruz and E. R. Williams, Department of Chemistry, University of California, Berkeley, CA 94720, USA.
4. O. Orwar and J. A. Lundqvist, Department of Chemistry, Göteborg University, SE-412 96, Göteborg, Sweden.
5. M. Sandberg, Department of Anatomy and Cell Biology, Göteborg University, SE-413 90, Göteborg, Sweden.