The in vitro T7 transcription system allows one to synthesize biochemical amounts of RNA molecules functionally equivalent or similar to those transcripts normally existing at extremely low levels in vivo. In this study we described a modified method for efficient large-scale preparation of pure T7 RNA polymerase free of RNase activity from the recombinant Escherichia coli strain BL21/pAR1219 (4). The procedure, which used preparative column chromatography on DEAE-Sepharose CL-6B and Blue 3GA, was shown to be simple, rapid, and cost effective in comparison with other methods reported previously.
Copyright 1999 Academic Press.