Factors Affecting the Conductivity of DNA

DNA sequence In an aperiodic sequence the disorder along the one-dimensional chain keeps changing the environments of the various bases, hence their energy positions are scattered over a much wider range of energy, thus affecting the overall band gap of the resultant DNA molecule. 

Length of the DNA chain For chains of small lengths the electronic properties depend on the length of the chain, but for sufficiently large chains the conductivity of the DNA molecule is independent of the length of the chain. 

Water and counter ions Since DNA is a charged molecule the presence of water and counter ions in its environment influences its structure and conduction behaviour. The A-DNA structure is obtained with 5-10 water molecules present per base, while for 13 water molecules per base the B structure results. 

---