E. coli S30 Extract System for Circular DNA Technical Bulletin

Literature # TB092

The E. coli S30 Extract for Circular DNA simplifies transcription/translation of DNA sequences cloned in plasmid or lambda vectors, providing a powerful tool to identify and characterize polypeptides. The investigator needs only to supply the cloned DNA containing the appropriate prokaryotic promoter and ribosome binding sites. The S30 Extract System for Circular DNA is prepared by modifications of the method described by Zubay from an E. coli strain B deficient in OmpT endoproteinase and lon protease activity. This results in greater stability of expressed proteins that would otherwise be degraded by proteases if expressed in vivo. The S30 Extract System for Circular DNA also allows higher expression levels of proteins that are normally expressed at low levels in vivo due to the action of host-encoded repressors.

Expression of the luciferase gene in the S30 System for Circular DNA can be assayed easily by non-radioactive methods using the provided Luciferase Assay Reagent. The assay produces high light output for several minutes, allowing the researcher to choose from several methods of detection, including simple visual observation of luminescence.