Patent ID: 8399217

Claim:
A method for promoting auto-induction, in bacterial cells grown batchwise, of a cloned gene 1 of bacteriophage T7, which gene is under the control of an inducible promoter selected from the group consisting of a lac promoter and an araBAD promoter, and which gene is adapted for stable propagation in said cells, the method comprising: a) providing a culture medium comprising: i) an inducer of said promoters; and ii) a concentration of one or more depletable culture medium constituents, which one or more constituents prevent induction by said inducer, the concentration of said one or more constituents being adjusted so as to substantially preclude induction by said inducer until such time as growth of the bacterial cells in the culture medium depletes the concentration of said one or more constituents to a level that permits induction by said inducer; b) inoculating the culture medium with an inoculum of said bacterial cells; c) incubating the culture of step b) under conditions appropriate for growth of the bacterial cells; and d) continuing to incubate the culture of step c) until depletion of the concentration of said one or more constituents has promoted auto-induction of gene 1 by said inducer.