Recombinant DNA

Review

• Restriction enzymes cut DNA molecules at certain ‘restricted’ points

• A plasmid is also cut at the same point

• The ends match up and DNA ligase forms a link between the dangling or sticky ends of the DNA

• Once the recombinant DNA is made then a host bacterium (often E. Coli) takes up the plasmid (it is ‘transformed).

• The bacteria that have taken up the recombinant DNA are selected.

• Then the bacterium produces the protein just as it would produce its own proteins.

• E. Coli is commonly used for recombinant DNA

• ECORI is also from E. Coli

• Genes are often stored in host , like E.Coli

Uses for recombinant DNA

Pharmaceutical productse.g. insulin, human growth hormone,

interferon

Vaccinese.g. hepatitis B vaccine

Diagnostic testinge.g. using DNA problem

Uses cont’d

Gene therapycells are taken from patient then modified and replaced

DNA fingerprintingused to find crime suspects and paternity cases

Gene therapy

DNA fingerprinting