Synthesis of [15N]-Labeled DNA Fragments

DNA fragments labeled with 15 N have the potential to provide novel insight into base pairing, hydration, drug/nucleic acid, and protein/ nucleic acid interactions. Synthetic routes to a variety of [15 N]-labeled pyrimidine nucleosides (1 –3 ), purines (4 –6 ), and purine nucleosides (7 –13 ) have been reported. In some cases these labeled bases or monomers have been incorporated into nucleic acids, either by chemical synthesis (9 ,10 ,14 –17 ) or by biosynthetic procedures (18 –22 ). The focus of this chapter will be on the preparation of [15 N]-labeled purine 2′-deoxynucleosides and their incorporation into DNA fragments by chemical synthesis.