lambda-Red genetic engineering in Salmonella enterica serovar Typhimurium.

The use of the recombination system from bacteriophage lambda, lambda-Red, allows for PCR-generated fragments to be targeted to specific chromosomal locations in sequenced genomes. A minimal region of homology of 30 to 50 bases flanking the fragment to be inserted is all that is required for targeted mutagenesis. Procedures for creating specific insertions, deletions, and site-directed changes are described.