Potassium persulfate crystal

5-Methyl-2'-deoxycytidine (5-Me-2'-dC) and 2',3'-dideoxy-5-methylcytidine (5-Me-2',3'-ddC) were obtained from Carbosynth Ltd. (Berkshire, UK). 2'-deoxycytidine, Thymidine (Thd), thymidine-3'-monophosphate (3'-TMP), thymidine-5'-monophosphate (5'-TMP), thymidine-5'-diphosphate (5'-TDP), thymidine-5'-triphosphate (5'-TTP), lithium chloride (LiCl) (99% anhydrous, SigmaUltra), and sodium perchlorate (NaClO₄) were obtained from Sigma Chemical Company (St Louis, MO, USA). 2',3'-dideoxy-5'-thymidine triphosphate (2',3'-dd-5'-TTP) was purchased from TriLink Biotechnologies (San Diego, CA, USA). 2',3'-dideoxyadenosine (2',3'-ddAdo) was obtained from Berry & Associates, Inc. (Dexter, MI, USA). Potassium persulfate (crystal) was obtained from Mallinckrodt, Inc. (Paris, KY, USA). Deuterium oxide (D₂O) (99.9 atom % D) was purchased from Aldrich Chemical Company Inc. (Milwaukee, WI, USA).

Lithium chloride (LiCl) (ultra dry, 99.995% (metals basis)) and lithium bromide (LiBr) (anhydrous, 99.99% (metals basis)) have been obtained from Alfa Aesar (Ward Hill, MA). 2′-deoxyguanosine 5′-monophosphate (5′-dGMP) has been obtained from Sigma-Aldrich (St Louis, MO). Potassium persulfate (crystal) and sodium nitrate have been purchased from Mallinckrodt, Inc. (Paris, KY). All compounds were used without further purification. We chose to use CNPs generated from cerium chloride and cerium nitrate for our ESR spectral studies.