title: Seeing what was unseen: new analytical methods for molecular imaging.
abstract: For nondestructive analysis of chemical processes in living cells, we developed novel intracellular fluorescent indicators for second messengers, protein phosphorylation, and protein/protein interactions that work in single living cells. Key molecules and steps of cellular signaling pathways were visualized under a confocal laser microscope in target live cells using developed fluorescent indicators. A second new approach to molecular imaging is also described. When chemically modified tips were used for STM measurements, contrast enhancements at specific regions in the STM images occurred on the basis of hydrogen bond and metal-coordination interactions. This enabled us to detect not only the distribution of specific chemical species and functional groups but also the orientation of functional groups. The contrast enhancements reflect the increase in a tunneling current due to the overlap of electronic wave functions induced by the chemical interactions between tip and sample.
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, and Japan Science and Technology Corporation (JST), Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. umezawa@chem-s.u-tokyo.ac.jp
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Umezawa
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D006860:Hydrogen Bonding; D008856:Microscopy, Fluorescence; D016252:Microscopy, Scanning Tunneling; D008968:Molecular Conformation; D015398:Signal Transduction
chemical_list: D005456:Fluorescent Dyes