| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
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| Research Abstract |
Singlet oxygen (^1O_2) has strong emission band at 1268 nm and weak bands at 1070 and 1580 nm. These bands result from a single molecule of ^1O_2 and directly proportional to the ^1O_2 concentration. Thus, the 1268 nm band, which is both strong and directly proportional to the ^1O_2 concentration, will be the most intense at low ^1O_2 concentration. This infrared emission can be used to search for ^1O_2 in biological systems.
We have constructed an apparatus for the measurement of near-infrared emission. It consists of a liquid nitrogen-cooled germanium detector (B2123, Hamamatsu) and interference filters (Vacuum Optics Co. of Japan) with maximum transmittance of 76 % and band width of 21 nm. Photocurrent was converted to voltage and amplified. After A/D conversion, data were accumulated by a computer and then analyzed. In NaOCl-H_2O_2 system, intensity of emitted light was dependent on the concentration of both NaOCl and H_2O_2. Using three interference filters (center frequencies are 1167,1266 and 1238 nm), the emitted light from the system has peak wavelength near 1270 nm. Before application for biological system such as leukocyte system, we examined assay conditions. Leukocytes could be activated by fatty acids even at 25 ﾟC , so we could reduce the effect of black-body radiation. Leukocytes were activated in deuterium water without addition of stimulators, therefore, we should take care the effect of deuterium water when we measure infrared emission in this medium.
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