Fig. 2

Antibiotic-free transformation. a Plasmid map of CGB289 showing the location of the restriction enzyme sites. b The engineered strain E. coli HS996-infA was transformed using infA selection with the plasmid CGB289. The purple pigmentation of the resulting colonies indicates that all colonies have taken up plasmid. c Ten isolated colonies were selected from the transformation plate and analyzed with a restriction digest using KpnI and Eam1105I. All samples displayed the expected banding pattern: 1353 bp, 965 bp and 531 bp