Method for confirming and selecting cells with altered DNA or newly introduced nucleic acid without using antibiotics

摘要

PROBLEM TO BE SOLVED: To select an Escherichia coli transformant using a commonly used Escherichia coli strain or vector without using an antibiotic resistance gene as a selection marker, and further to establish an experimental system in which the process can be visually and firmly learned. To develop. SOLUTION: Escherichia coli JM109 transformed with a plasmid having the lacZ gene is selectively grown in a liquid medium containing no antibiotics, and it is confirmed whether it is transformed by a color change, or Visually see how the number of transformed cells increases. Then, a part of the liquid medium is smeared on an LB medium (including X-gal) to confirm the ratio of transformed cells or to select transformed ones. [Selection diagram] Figure 2