After the new DNA has been cut by restriction endonuclease forming a sticky end, the same restriction endonuclease is used to cut a host plasmid. This then leaves a space in the plasmid with sticky ends that compliment the bases on the end of the cut DNA meaning that the DNA will fit into the plasmid.
DNA ligase is used in order to join the plasmid to the DNA.
Transformation into host cell:
Plasmids are placed into a test tube with bacteria and calcium ions. The change in temperature and the calcium ions make the bacteria permeable. Some of the bacteria will take up the plasmids, others may not as they may have closed back up again.
Finding out which bacteria have taken up the plasmid:
The plasmid had the genetic resistance for ampicillin.
All the bacteria are then grown in a medium with ampicillin.
The bacteria who haven't taken up the plasmid will not be resistant to the ampicillin and will therefore die.
Some of these cells…