INTRODUCTION OF 5'-TERMINAL AMINO AND THIOL-GROUPS INTO SYNTHETIC OLIGONUCLEOTIDES

Oligonucleotides terminating in a 5'-primary amine group are synthesized using solid phase phosphoramidite chemistry. The 5'-terminal amine group in the deprotected oligonucleotide is further derivatized with N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP) followed by treatment with dithiothreitol (DDT) to produce 5'-thiol terminated oligonucleotides. Introduction of 5'-thiol group is further confirmed by reading the absorbance of the released chromophore, pyridine-2-thione at 343 nm; epsilon-343 = 8080/M.