Laboratory of Nanobiology


Professor Yoshie HARADA
Assistant Professor Hisashi TADAKUMA



Tel +81-6-6879-8627
Fax +81-6-6879-8629


Biomolecules that function in our bodies come in a variety of sizes ranging from several to hundreds of nanometers.  This size falls precisely in the “meso” domain, which lies at the junction between micro and macro levels. A key difference in the environments of humans and biomolecules is that it is impossible for biomolecules to ignore thermal fluctuations because they are constantly exposed to changes in heat. Thus, unlike artificial machines, biomolecules are able to make skillful use of thermal fluctuations while functioning. For example, RNA polymerase is one-dimensionally diffused on DNA when searching for a promoter site. Our ultimate goal is to elucidate the how biomolecules operate.

Observing the motions of individual molecules and manipulating molecules directly are very useful for learning the working mechanisms of biomolecules. Therefore, we have developed techniques such as single-molecule imaging microscopy capable of directly observing the motion and structural changes of individual molecules, a method of manipulating molecules by grabbing molecules with optical or magnetic tweezers, and an apparatus for measuring the minute forces generated by molecules. Today, we are developing new imaging technologies and use these techniques to investigate the molecular mechanisms of biomolecules.


Current Research Programs

  1. Development of a novel single-molecule imaging technique using fluorescent diamond nanoparticles


2. Analysis of biomolecular interactions with zero-mode waveguides


3. Molecular mechanism of epigenetics





  1. Reversible Morphological Control of Tubulin-Encapsulating Giant Liposomes by Hydrostatic Pressure. Hayashi, M. et al.(2016)
    Langmuir 32(15), pp 3794–3802
  2. The application of fluorescence-conjugated pyrrole/imidazole polyamides in the characterization of protein–DNA complex formation.
    Han, YW. et al.(2016)Sci.4, 391-399
  3. Synergistic effect of ATP for RuvA-RuvB-Holiday junction DNA complex formation. Iwasa, T. et al.(2015) Scientific Reports 5, 18177
  4. Suppression of Nonspecific Protein-Nanodiamond Adsorption Enabling Specific Targeting of Nanodiamonds to Biomolecules of Interest. Sotoma, S. et al.(2015) Chemistry Letters 44(3), 354 - 356
  5. ECHO-liveFISH: in vivo RNA labeling reveals dynamic regulation of nuclear RNA foci in living tissues Nucl. Oomoto, I. et al. (2015) Nucleic Acids Res.43(19), e126
  6. Comprehensive and quantitative analysis for controlling the physical/chemical states and particle properties of nanodiamonds for biological applications. Sotoma, S. et al.(2015) RSC Adv.5, 13818 - 13827
  7. Optically Detected Magnetic Resonance of Nanodiamonds In Vivo; Implementation of Selective Imaging and Fast Sampling. Yoshinari, Y. et al.(2015) J Nanosci Nanotechnol. 15, 1014 - 1021