The multiple cloning site (MCS) of the pJet1.2 plasmid also contains a gene that encodes an enzyme lethal to E. coli. If the gene is not interrupted by a DNA insert, then the enzyme will be produced, killing the bacteria. However, if a DNA insert is ligated into the MCS, the gene will be interrupted, thus no enzyme will be made, and the colony would survive.
Based on your answer in Question 7, which transformants would result in colonies?
1. Linearized, unligated plasmid
2. Religated plasmid with no DNA insert
3. Plasmid with desired DNA insert
4. Plasmid with undesired inserts
5. DNA inserts