A short, novel, and cheaper procedure for oligonucleotide synthesis using automated solid phase synthesizer.

Dimethylthiuram disulfide (DTD) has been developed as an efficient thiolation reagent during automated synthesis of oligonucleotides using phosphoramidite chemistry. Simultaneous thiolation and capping was accomplished by mixing DTD with capping solution B, which saved 20% of solvent consumption and compressed the four-step synthesis cycle to three. Large-scale (1 mmol) synthesis of phosphorothioate oligonucleotides has been demonstrated with excellent yield and purity.