T7 Enhanced Library

The T7 RNA polymerase enhanced promoter library contains thousands of novel T7 mutant promoters that cover a wide range of expression activity compared to the wildtype T7 promoter. This library is the most comprehensive tool set available to researchers that enable control of essentially any gene in E. coli at any practical expression level. The promoters can be used to drive expression for low yield proteins or optimize complex metabolic pathways, making the library ideal for:

  • Bio manufacturing facilities with a need to increase titers and yields
  • Synthetic biology and metabolic engineering researchers optimizing production chassis
  • Small molecule producers who need to increase their production output

The library is organized into expression levels as depicted in the diagram below. This product structure gives researchers a low cost entry into testing novel T7 promoters for research use before committing to a production facility. We’ve structured our library this way to facilitate transferring protein production from the lab to large scale facilities. For details and culturing conditions, please read our white paper.


This product contains 5 novel T7 mutant promoters that represent expression levels evenly spread out between 1-100% (relative to the wild type T7 promoter). Weaker promoters are invaluable tools that allow researchers to easily and efficiently direct carbon flow in certain metabolic pathways and optimize their host chassis for small molecule production.


This product contains all our promoters with transcriptional activity below the wild type T7 promoter. With almost 2800 novel promoters, this library provides exceptionally fine expression control for activity from 1-100%.


This product contains 5 novel T7 mutant promoters that represent expression levels evenly spread out between 100-200% (relative to the wild type T7 promoter). This library is an excellent low cost entry to facilitate testing of promoters with increased activity. The T7-3 library currently includes 96 individual promoters.


This product includes any single promoter with activity above 200% (relative to the wild type T7 promoter). The T7-4 library currently includes 35 individual promoters that range in activity from 202-553% (relative to the wild type T7 promoter). We are continually testing the thousands of additional promoter candidates from our original experiment, so check back to see if we’ve added any new promoters since the last time you checked.

Depending on the availability of transcriptional machinery (ie available ribosomes, transcription factors, chaperones, etc.), your host may not have the capacity to reach some of these higher expression levels. For that reason, we recommend trying the T7-3 library first, to confirm your host has the capacity to support higher protein expression levels.


This product includes all the mutant T7 promoters in our library. The library currently includes 2905 individual promoters.

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For more details regarding prices and availability, please contact us.