Electron Spin Resonance of Gamma-Irradiated Oriented DNA Prepared by Wet Spinning

Abstract

When moist, oriented DNA is gamma-irradiated and its electron spin resonance spectrum is recorded at 77°K, an unresolved spectrum is obtained, the amplitude of which is strongly dependent on the angle between the direction of the DNA helices and the field. Annealing at 199°K gives an eight-line thymine-like spectrum which also has a marked angular dependence. For dry, oriented DNA, the unresolved spectrum dominates even at room temperature, and the spectra exhibit lower degrees of anisotropy.