Some Pulse Radiolytic Observations on the Reactivity of Hydroxyl Radicals with DNA and Poly A

SummaryThe apparent reactivity of DNA to OH radicals, as measured by the thiocyanate competition method, proved to be dependent on the absolute concentrations at a constant concentration ratio of CNS− to DNA. This phenomenon could be explained qualitatively as being the consequence of the inhomogeneous distribution of the nucleotides in DNA solutions.Single stranded DNA and polyadenylic acid showed an increased reactivity to OH radicals when compared with the double-stranded forms of the same polymers.