TOP > > Tomoji Kawai
Tomoji Kawai 川合 知二
Scientists website
By adding the voltage of electrodes (gate electrodes) created in the nano flow paths, with DNA single-molecule flowing through channels (nano flow paths) with nanometer-sized width and height, we succeeded in controlling the flow speed of DNA singlemolecule using electricity. This has enabled us to carry out accurate readings. (May 2012)
Harnessing leading-edge semiconductor technology, we are the first in the world to succeed in determining the singlemolecule sequence of DNA and RNA. We have achieved this by fabricating electrodes that have a distance of approximately 1 nanometer between them, which corresponds to the size of one base molecule*1, and by continuously measuring the electrical resistance of one base molecule. This represents significant progress toward the realization of early diagnosis methods for diseases for early prevention. (July 2012)

Nanobiotechnology Dramatically Reduces Medical Costs
The progress of various analytical technologies in the medical field steadily establishes the practical application of innovative nanobio devices. This is expected to enable home-diagnosis and early discovery of diseases, and dramatically reduce medical costs.

Nano-size biotechnology enables homediagnosis and early discovery of illness The ultra-high speed analysis of DNA base sequence; ultra-low density, ultra-high-speed detection of viruses; and ultra-high sensitivity, ultra-high speed detection of allergens such as pollen promise easy diagnosis of various illnesses. Innovative nanobio devices (micro devices for biological measurements) applying these technologies will enable home-diagnosis and early discovery of diseases, and are thus expected to dramatically reduce medical costs. With hopes that the single-molecule identification of protein and DNA will enable ultra-high speed and ultra-high sensitivity diagnosis of diseases not possible with conventional techniques, companies, universities, and national agencies are working together to develop techniques to detect and separate single-molecules using gating nanopores (technology of measuring the current cutting across nanosize pores, which are small and can only be passed by molecules) and nanopillars/nanowalls (technology of detecting and separating single-molecules using nanosize structures such as nanosize pillars and walls) to realize diagnosis of infections by virus tests, diagnosis of cancer by RNA testing, and diagnosis of breath and urine.


Aiming to cut medical costs and establish tailormade medical care through high-speed analysis Even with the latest technologies available today, it takes about 100,000 dollars and two months to analyze the DNA base sequence of one person. If ultra-high speed analysis technology is practically available one day, it will be possible to complete this in just one day, at just 100,000 yen. Researchers worldwide are thus competing against one another to develop the technology. The analysis of DNA base sequence which differs slightly in each person will help predict and prevent cancer, and realize tailor-made medical care, providing the best treatment and medication free of side-effects for each patient.


figure