The kanamycin cassette fused with a promoter is more efficient than ermF-ermAM in the activation of TDE1430. (A) Transformation efficiency of the kanamycin cassette. Transformation was conducted as described in Materials and Methods—without DNA (panel a1, Control), with 15 μg of linearized TDE1430P1aphA2 (panel a2), or with TDE1430-ermF-ermAM (panel a3)—and then the samples were plated onto appropriate agarose media to select transformants. (b) Colonies from diluted samples were counted and presented as CFU/μg of input DNA (bars represent the average of three transformation experiments). (B) PCR confirmation of the deletion of TDE1430. Ten colonies were examined by PCR for insertion of the kanamycin cassette (a), loss of TDE1430 (b), and orientation of the kanamycin cassette (c and d). (e) Diagram of the TDE1430 deletion allele represents the structure of plasmid VIII.