Although deoxyribonucleic acid (DNA) is a relatively stable chemical substance, it’s damage is often caused by various factors. While the stability of DNA investigated by both experimental and theoretical studies, there is not information to show how true coding in DNA replication is guarantied energetically. In this study the stabilization energy and reactivity of different possible base pairs including Adenine (A), Thymine (T), Cytosine (C) and guanine (G) estimated and compared to each other. The results show that AT and GC base pairs are considerably stable than the other possible outcomes. It is known that hydroxyl radical is on of the highly reactive species which can interact with DNA and induces DNA double strand-breaks. The previous investigations show that the hydroxyl radical can stably exist near the hydrogen bond between adenine and thymine, or between guanine and cytosine. In this study the effect of hydroxyl radical on the stabilization and reactivity of different possible base pairs were also investigated.
