Charge transport mechanism in native deoxyribonucleic acid

The frequency dependent electrical conductivity below 1MHz was studied on wet-spun, macroscopically oriented, calf thymus DNA bulk samples. Temperature dependence of the quasistatic electrical conductivity measured perpendicular to the long DNA axis is discussed within the framework of activated variable range hopping mechanism. It is shown that the frequency dependence of the electrical conductivity in the frequency range of approximately 10(-3) Hz-10(15) Hz agrees well with predictions of the hole hopping mechanism. Temperature dependence of the electrical conductivity at various frequencies exhibits a crossover at lower temperatures to almost temperature independent mechanism.