Comparison of PCR product sizes from ATCC 47076 and ATCC 700926 cells by amplifying the ychE and crl genomic regions. Primer sets are given in Table 2. (A) Gel showing amplified fragment sizes in the absence and presence of insertions. The leftmost lane contains Invitrogen 1 kb Plus DNA ladder. Relevant lanes: 1, ychE primers, no template DNA; 2, ychE primers, ATCC 47076 DNA; 3, ychE primers, ATCC 700926 DNA; 4, crl primers, no template DNA; 5, crl primers, ATCC 47076 DNA; 6, crl primers, ATCC 700926 DNA. Gel lanes from an unrelated experiment have been cropped from the image. Expected product sizes based on the reference sequence are ∼750 bp (crl gene) and ∼850 bp (ychE gene). (B) Schematic showing the location of each insertion relative to nearby genes and the primers. Interprimer distances are in the absence of the insertion.