How Genetic Engineering is Done

How Genetic Engineering is Done

1. 1. Extraction of required gene from [human] cells from other DNA

   • Using restriction enzymes: they cut DNA molecules at particular points
     • Leave unpaired bases at each end called 'sticky ends'

2. 2. Insertion of gene into bacteria using plasmids

   • Plasmids: a ring of DNA found in bacteria

3. 3. Plasmid is cut, using the same restriction enzymes.

   • Leaves sticky ends complementary to those of the gene

4. 4. Genes and plasmids are mixed together using DNA ligase. Product: Recombinant Plasmids

   • DNA ligase: enzyme that firmly links strands of genes and plasmids together

5. 5. Added to a culture of bacteria, put into fermenters, and allowed to reproduce asexually.