Biotechnology gene cloning and Polymerase chain reaction

Gene cloning

  • Isolates and creates copies of a gene
    • Useful for gene therapy
  • 4 steps
    • Isolation
    • Ligation
    • Transformation
    • Selection

Isolation

  • An enzyme is used to break DNA at a specific base sequence. This isolates the gene

Ligation

  • The enzyme DNA ligase combines the isolated gene with plasmid DNA from bacteria
    • Plasmid DNA is circular DNA that is not part of a chromosome and can replicate independently
  • The resulting DNA is called @@Recombinant DNA@@

Transformation

  • The recombinant DNA is inserted into a living cell (usually bacteria)
    • This change is also called @@genetic engineering@@

Selection

  • Growing transformed bacteria to ensure they have the recombinant DNA
  • Important as transformation is not always successful

Polymerase chain reaction (PCR)

  • Creates copies of a gene or other DNA segment
  • Used to make large quantities of a gene for genetic testing
  • 3 Steps
    • Denaturing
    • Annealing
    • Extention

Denaturing

  • Heating DNA to break the bond holding the 2 DNA strands together
  • Creates 2 single DNA strands

Annealing

  • Cooling the single strands and mixing them with short DNA segments called primers
  • Primers have sequences complementary to segments on the single DNA strand
  • Bond forms between strands and primer

Extention

  • An enzyme adds nucleotides to the primers
  • This creates new DNA molecules each incorporating one of the original DNA strands