Protocol for the expression of cloned genes in E. coli using IPTG-inducible promoters. Protocol describes how (1) to clone cloned sequences encoding open reading frames in plasmids carrying IPTG-inducible promoters, (2) to optimize expression of target proteins in transformants carrying these recombinants, and (3) to scale-up production of foreign proteins. - [Read Expression of Cloned Genes in E. coli Using IPTG-inducible Promoters Protocol]
An expression library constructed in a bacteriophage {lambda} vector is plated on an appropriate E. coli strain in the absence of isopropylthio-ß-D-galactoside (IPTG). After 2-4 hours, the plates are moved to 37°C (to stabilize any fusion proteins that are temperature sensitive), and filters impregnated with IPTG are laid on top of the developing plaques. - [Read Screening Expression Libraries Constructed in Bacteriophage Lambda Vectors Protocol]
A cDNA library constructed in a plasmid expression vector of the pUC, pUR, or pEX series is plated on agar medium and then replicated onto filters, which are transferred to plates containing IPTG. After 2-4 hours of induction, the colonies are lysed with chloroform and then screened with appropriate antibodies. - [Read Screening Expression Libraries Constructed in Plasmid Vectors Protocol]