Abstract:The mixture of deoxyribonucleoside, dCTP, dTTP, dGTP and dATP at concentration of 100 μmol/L for each, was treated by 75 mmol/L of chlorine dioxide for 10 min, high performance liquid chromatographic analyses indicated that all of the four decreased in peak area by 54.23%±2.08%, 66.25%±3.32%, 55.47%±0.23%, 59.59%±3.27% respectively at wavelength of 260 nm. For 0.2 μg/μL of purified plasmid DNA, their activity as template in polymerase chain reaction were completely inhibited by chlorine dioxide at concentration of 45 mmol/L or above, and the transformation rate decreased to 0.20%±0.2% when treated by 75 mmol/L of chlorine dioxide. Our result indicated that chlorine dioxide have substantial damages on deoxyribonucleoside and plasmid DNA.