Quick Transformation with Plasmid DNA

Genomic engineering of Escherichia coli and Salmonella often requires introducing plasmids into strains obtained during the intermediate stages of the process. Such strains are typically transformed only once, making the preparation of large batches of competent cells for storage purposes unnecessary. Here, we describe a simple scaled-down procedure for transforming E. coli or Salmonella with plasmid DNA that uses as little as 2 mL of culture.