Whether or not DNA acts as an effective electron transporter has been a controversial issue since the 1960s, when Ely and Spivey first predicted the possible electroconductivity of the genetic carrier<sup>1</sup>. Recent studies have shown conclusive evidence that DNA exhibits properties of a molecular wire; electrons travel through the pi-stack of matched base pairs. In our study, we coated bulk-gold electrodes with various DNA sequences and quantized the density of our DNA mono-layer through electrochemical assays. We then used the DNA mono-layers to study the intercalating effects of bleomycin, an antibiotic, on DNA electroconductivity with and without oxygen in solution. Oxygen activates bleomycin?s ability to cleave DNA and would therefore be an effective chemotherapeutic agent, if it were not so cytotoxic. In brief, we found that the intercalation into the DNA, slightly affects the electrochemistry of bleomycin, changing its reduction/oxidation potentials. <sup>1</sup>Kelly, S.O.; Jackson, N.M.; Hill, M.G.; Barton J.K. Angew. Chem. Int. Ed. 1999, 38, 941.