The Process of Genetic Engineering

There are a few steps in the process of genetic engineering:

1. The desired characteristic is selected.

  • This gene is located in the original organism

2. Restriction enzymes are used to cut out the gene that is responsible for the characteristic. However, this leaves ‘sticky ends’ (sections of DNA that have unpaired bases).

  • DNA ligase is an enzyme that can join together sticky ends if the nucleotides on the strands are complementary

3. The vector must be cut with the same restriction enzymes, which leaves complementary sticky ends

4. The gene is inserted into a vector.

  • This vector is usually a bacterial plasmid (a small circle of DNA) or virus

5. The vector is used to insert the gene into the cells of the target organism.

The genes must be inserted into the cells of the target organism during the early stages of its development. In animals, the early stage of development is the early embryo stage. This is to ensure that all of the cells receive the gene, and that the organism develops with the desired characteristics.

The diagram below shows the genetic engineering of E. coli (a type of bacteria) with a foreign gene.