Die Erzeugung atomaren Wasserstoffs in γ-bestrahlten Bakteriophagen und in deren DNS

Abstract

ESR-spectra of purified preparations of bacteriophage and of DNA extracted from these objects were found to contain the characteristic lines of atomic hydrogen after γ-irradiation at 77 °K. The experimental results demonstrate the production of atomic hydrogen by irradiation of organic materials in a direct way. The high stability of the trapped hydrogen atoms is indicated by the fact that heating to 200 °K for 10 min reduces the spectral amplitudes by a factor of two only. The yield of trapped atomic hydrogen varied between 0.05 and 0.6 while the total radical yield derived from the ESR-spectra was found between 1.0 and 3.0. Addition of moisture to vacuumdried samples did not enhance the yield of H-atoms. At 50% water content the yield was also reduced to about 50% other parameters remaining unchanged. The disappearance of hydrogen lines on heating is accompanied by an enhancement of the octet spectrum due to the addition of atomic hydrogen to thymine groups. The observation of H-stabilization in inorganic phosphates is taken to suggest trapping by phosphate groups in DNA. The efficiency of trapping is probably influenced by the presence of impurities, notably transition metals. The apparent g-factor of 2.014 ± 0.002 is explained by IS-coupling. The true g-factor obtained by application of the Breit - Rabi formula is equal to the free electron value within experimental limits of error.