Advances in the chemical synthesis and purification of RNA

Significantly developments that improve the chemical synthesis and purification of oligoribonucleotides have been attained. Introduction of a 2'-O-acetyl function on the nucleoside bound to the polystyrene support enhanced the yield of the oligoribonucleotide after cleavage. Higher coupling efficiency was achieved by the activation of phosphoramidites with a 0.75M solution of 5-ethylthio-1 H-tetrazole. Removal of the 2'-O-t-butyldimethylsilyl groups was effected rapidly at elevated temperatures with triethylamine trihydrofluoride in DMF. Fully deprotected RNA was then directly desalted and precipitated by the addition of 1-butanol. Purified RNA was isolated by the addition of 1-propanol to the collected HPLC purified fractions thus avoiding laborious desalting and solvent evaporation processes. These advancements have been extended to synthesis of ribozymes and tRNA.