Comparison of in vitro transcriptions using various types of DNA templates.

Improvements in the synthesis of RNA using T7 RNA polymerase and synthetic deoxyoligonucleotides containing the T7 RNA promoter are described. Yields were highest when the double-stranded promoter was generated from a hairpin hybridized to the single-stranded DNA template or when the templates were assembled by ligation of shorter chemically synthesized deoxyoligonucleotides. Our results show that for the synthesis of RNA, templates prepared by ligating smaller deoxyoligonucleotides were as much as 25 times more efficient than those prepared by one-step chemical synthesis.