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4.3 outline the procedure to produce recombinant DNA
outline the procedure to produce recombinant DNA
- Human insulin is made using recombinant DNA. The Eschericia coli bacteria are used to do this in the following way:
- The human gene for making insulin is cut out of the chromosome taken from a human pancreas cell (Islets of Langerhans cell) using an enzyme called restriction enzyme.
- A ring of DNA called a plasmid is removed from the E.coli bacterium and cut open with a restriction enzyme.
- The human insulin gene is mixed with the cut plasmid. All of the cut ends (“”sticky ends””) can bond together using the enzyme DNA ligase to make a new DNA molecule.
- The “”new”” plasmid, that contains the recombinant DNA, is inserted back into the bacterial cell.
- When the bacterial cell reproduces, so does the plasmid and hence the human insulin gene. When provided with the appropriate nutrients, these cells produce human insulin which can be extracted and used by diabetics.
- Recombinant DNA can also be used in:
- the production of human growth hormone
- a protein that dissolves blood clots and so can be used to treat heart conditions
- bacteria to break down toxic waste in oil spills
- pest resistance in some plants, such as giving cotton resistance to the cotton boll weevil.