Recombinant DNA Lab

During the Recombinant DNA lab, we modeled recombinant DNA technology to show how bacteria can be used to mass produce a protein product. We were given paper strips that represented cell DNA once we attached them into a long string. We also created a plasmid, which is circular DNA that is found in bacteria, by attaching a strip to itself. Plasmids are naturally resistant to a certain antibiotic; in our case, the plasmid was naturally resistant to the antibiotic kanamycin. 

During transformation, restriction enzymes cut DNA in a staggered fashion (above and below) whenever they recognize a specific sequence. After cutting out the specific gene, it will be placed into the plasmid by bonding their sticky ends(ends of cut gene that will attach to the plasmid). The plasmid also has the same sequence, which is cut out and replenished by the cell DNA. In our lab, we used the enzyme Eco RI because there were two matches on the cell DNA, close to the gene, and another match on the plasmid. The plasmid is cut in only one place because if an enzyme was to cut in two places, part of the plasmid would be removed before the gene was inserted. After all this, the enzyme ligase is added, which reattaches the sticky ends. At this point, a recombinant plasmid has been created.


Now, you would put the bacteria in a petri dish along with a naturally resistant antibiotic. In our case, this was kanamycin. We couldn't use  tetracycline or ampicillin because the plasmid wasn't resistant to those. This would test whether any uninvited cells have taken in the plasmid because only the cells with the plasmid would survive. When the bacteria containing the plasmid reproduce, they will begin to produce the gene product.

This process is vital in our everyday lives for mass producing a protein product that will be useful to us, such as insulin for diabetics. Recombinant DNA technologies could also be used to delay food expiration by making it last longer, as well as resistance to pesticides.