General Lab Information

Technologies Available for License

2002-021: Media for suppression of Auto-induction in Expression Strains

Invention: 2002-021

Patent Status: U.S. Patent Number 8,241,887 was issued on August 14, 2012

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TCP Technology

F. William Studier

Media for maintenance growth of T7 gene expression strains carrying expression constructs with suppression of unintended induction are provided in this patent. The unintended induction of expression strains is the cause of loss of the expression plasmid from the cells, such that all surviving cells lack the gene expression construct. The media and methods of this invention avoids unintended expression and results in preservation of the the expression strain, even for genes encoding toxic proteins.


In T7 expression host strains, any basal level expression of the T7 RNA polymerase (unintended induction) may lead to loss of the expression construct from the cells. To avoid this, special defined media and methods for their use have been developed and are covered in this patent. The various media are available commercially or may be made from the details in the patent specification.


Valuable expression constructs and the expression strains may be maintained indefinitely without loss of the expression construct. Thus, maintenance and verification activities are minimally required.

Applications and Industries

All companies manufacturing recombinant proteins will benefit from the use of the auto-induction media. No inducer is needed, no monitoring of cell cultures is required, resulting in increased efficiency and lowered costs. When making proteins that are normally toxic to the expression host cell, this media and methods for use provides a stable host expression strain.

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