Synthesis of RNA by in vitro transcription

In vitro transcription is a simple procedure that allows for template-directed synthesis of RNA molecules of any sequence from short oligonucleotides to those of several kilobases in μg to mg quantities. It is based on the engineering of a template that includes a bacteriophage promoter sequence (e.g. from the T7 coliphage) upstream of the sequence of interest followed by transcription using the corresponding RNA polymerase. In vitro transcripts are used in analytical techniques (e.g. hybridization analysis), structural studies (for NMR and X-ray crystallography), in biochemical and genetic studies (e.g. as antisense reagents), and as functional molecules (ribozymes and aptamers).