New laser system allows for prolonged examination of living cells
MASAAKI DEMURA, Nikkei staff writer
TOKYO -- A new super high-resolution microscope that uses two lasers has been developed by a research team led by professor Takayoshi Kobayashi at Tokyo's University of Electro-Communications.
The new microscope makes it possible to observe cells and tissue of living creatures in color at a resolution of 100 nanometers.
The new laser microscope is less likely to damage living matter. It is able to observe living material for long periods while keeping the subject alive because its laser beams are weaker than those of conventional products.
Semiconductor lasers already being used for industrial applications can also be used in the new microscope, meaning equipment cost savings of up to 90%.
Professor Kobayashi's research team now aims to commercialize their laser microscope within two to three years, targeting universities and corporate research institutions.
The development of the new microscope comes in response to research needs for an instrument capable of observing cell and tissue matter at high resolutions while keeping the examined subject alive.
Conventional technology poses risks to samples. Fluorescence microscopes currently used for examining cells label samples with fluorescent proteins and then irradiate them with lasers. Observing objects as small as 200 nm or less in diameter requires strong lasers. But this kind of powerful equipment is expensive and far more likely to damage cells, making it difficult to observe them for long periods without killing them.
The new microscope's two lasers have different purposes. One heats the sample, while the other observes it. First, cells and tissue must be labelled with marker molecules that react to light from the laser. Then the heating laser is used. When irradiated by the laser the marker molecules produce heat which causes changes in the refractive indices of the matter. The observations laser is then used to examine the changes in refractive indices to create images.
The use of multiple lasers with different frequencies to detect refraction changes makes it possible to observe the frequency distributions of various marker dyes simultaneously.
There are a variety of maker dyes that do not emit fluorescence which can be used as marker molecules. Hemoglobin and other proteins found naturally in the body of living creatures can also be used.
Unlike gas laser microscopes, the newest laser microscope can be transported by car and used for outdoor analysis. It can also be used to inspect for defects in large-scale integrated (LSI) circuits.