Generation of Nonpolar Deletion Mutants in Listeria monocytogenes Using the "SOEing" Method.

The ability to manipulate chromosomally encoded genes is a fundamental biological tool for the analysis of gene function. Here, we provide in greater depth a protocol for the creation of nonpolar unlabelled gene deletions in Listeria monocytogenes that are facilitated by the splicing overlap extension PCR technique. For mutagenesis in L. monocytogenes, we describe the pKSV7 plasmid-based approach, which facilitates the introduction of a spliced amplicon in place of the corresponding segment of chromosomal DNA.