Genetic engineering

• The gene must be identified and isolated from Donor DNA (a gene that is isolated for insertion)
• The gene for insulin is isolated using a gene probe.

Using reverse transcriptase

• Functional mRNA coding for insulin is found within the pancreas.
• The mRNA is extracted.
• Reverse transcriptase (made by retroviruses) is added to make a complementary DNA copy
• The addition of DNA polymerase converts it into a double strand for insertion into a plasmid.

To insert a gene into a bacterium, a vector is used. Usually a plasmid. (circular DNA from a bacteria.

• The plasmid is obtained by dissolving the bacterial walls and plasmids are seperated from the debris.
• The plasmid is cut open using the same restriction endonuclease which hydrolyses the internal sugar phosphate bonds between nucleotides within the DNA. They…