Figure 1. Summary of paramagnetic labeling strategies used in this study.
(a) The sequences of three DNA molecules that were synthesized and used in this study. “u” denotes deoxy-4-thiouracil and the red “T” denotes the 3′-end of phosphothioate. (b) The spin-labeling strategies using both modified base and phosphothiate are employed as depicted here. Both deoxy-4-thiouracil and the 3′-end of phosphothioate reacts with 3-(2-Iodoacetamido)-proxyl and thus allowed the covalent attachment of the spin-label to one end of a DNA molecule.