  Measurements of electron transfer rates as well as of charge transport
characteristics in DNA produced a number of seemingly contradictory results,
ranging from insulating behaviour to the suggestion that DNA is an efficient
medium for charge transport. Among other factors, environmental effects appear
to play a crucial role in determining the effectivity of charge propagation
along the double helix. This chapter gives an overview over charge transfer
theories and their implication for addressing the interaction of a molecular
conductor with a dissipative environment. Further, we focus on possible
applications of these approaches for charge transport through DNA-based
molecular wires.
