Using this system we routinely identify more than 100 click here recombinants per experiment in both laboratory and pathogenic E. coli strains, using short regions of homology to the chromosome, thus maintaining both a high-throughput and broad-range compatibility system. G-DOC plasmids The pDOC plasmids are derived from pEX100T, a medium copy number plasmid which carries ampicillin resistance and the B. subtilis sacB gene [19]. We have introduced different DNA sequences into the pEX100T I-SceI restriction sites to create a suite of plasmids, schematic diagrams of which are shown in Figure 1. The

cloning plasmid, pDOC-C, has a large cloning region (CR) flanked by two I-SceI recognition sites. The DNA sequence of pDOC-C, from 100 bp upstream of the left-hand I-SceI site to 100 bp downstream of the right-hand I-SceI site is shown in Figure 2, panel A. The template plasmid, pDOC-K, carries a kanamycin resistance cassette flanked by Flp recombinase GSK2118436 cell line recognition sites (Flp1 and Flp2). On either side of this region are 2 cloning regions (CR1 and CR2). The

other template plasmids, pDOC-H, pDOC-F, pDOC-P and pDOC-G are derivatives of pDOC-K that have the coding sequence for a 6 × His, 3 × FLAG, 4 × Protein A and GFP tag respectively, immediately downstream of CR1. Figure 2; panel B, shows the DNA sequence common to all of the pDOC template plasmids, from 100 bp upstream of the left-hand I-SceI site to 100 bp downstream Chloroambucil of the right-hand I-SceI site. The template plasmids differ between the CR1 and FLP1 sequences: this region is outlined by an open box in the figure. The DNA sequence 4SC-202 molecular weight proceeds through CR1, along the respective DNA sequence for each plasmid

within the open box, and into the FLP1 sequence below. The plasmid pDOC-K has 30 bp of DNA sequence prior to FLP1. The plasmid pDOC-H has the coding sequence for the 6 × His tag and a stop codon followed by a short DNA sequence leading into the FLP1 site. The first 10 codons of the 3 × FLAG, ProteinA and GFP tags are shown, followed by the stop codon and short DNA sequences leading into FLP1 site. Other features indicated on the DNA sequences of the pDOC plasmids in Figure 2 are described in the G-DOC recombineering protocol below. The full DNA sequence of each pDOC plasmid is provided in Additional file 1 and is also available from GenBank, accession numbers GQ88494-GQ889498. Figure 1 The pDOC donor plasmids. Circular representation of the pEX100T plasmid showing the location of the origins of replication, the sacB gene and the ampicillin resistance gene. Below is a linear representation of the pDOC plasmid inserts, showing the I-SceI restriction sites, cloning regions (CR, CR1 and CR2), the Flp recognition sites flanking the kanamycin resistance cassette (KanR) and the location of the epitope tags in plasmids pDOC-H, pDOC-F, pDOC-P and pDOC-G. Figure 2 DNA sequences of the pDOC plasmids.