Host: The Japan Radiation Research Society
"How are the chemical structure,the yield,and the distribution of DNA damage (DNA damage spectrum)caused by the ionizing radiations different by the radiations quality and their energy?" The answer to this question becomes a vital information in clarifying the mutation and the carcinogenesis mechanism following to DNA damage. However, the unified view concerning this question has not been obtained because of a lot of uncertainties in the status of DNA, in the variety of DNA damage and in the distribution of radical scavengers and in the possibility of the directly and indirect effects, in the oxygen concentration, and furthermore in the artifact, etc., regardless of the long-term investigation for the past several ten years. Another reason why DNA damage research by radiations has not been advanced should be that there has not been enough analytical methods to detect the damage because irradiated DNA is extremely delicate against temperature and pH. Then, we have developed DNA damage spectrum analysis method that doesn't strictly stick to the chemical structure of individual damage and is not influenced easily by the weakness of irradiated DNA. This method makes us possible to quantify 3'termini with or without phosphate and the electron-withdrawing damaged bases and abasic sites piperidine-labile sites using phosphodiestertase I and alkaline phosphatase. We would like to introduce how DNA damage spectrum can be analyzed by this method, and discuss it by comparison with other information.
