Definitions:
Biotechnology: Technology used to manipulate DNA
Genetic Engineering: Procedures used in biotechnology
Recombinant DNA: DNA from two different sources
Transgenic organism: Individual that received gene from
another species
Genetic Engineering Products:
Flavor Saver Tomato: A tomato that has been genetically
altered to maintain the flavor longer
Human Insulin, Human Hormones (HRT), Vaccines:
medical products made from inserting human DNA into
bacteria
Bovine Growth Hormone: used by dairies to increase
milk production by 10%
WHY? Bacteria produces MUCH faster than
humans
HOW? Restriction Enzymes:
 Found in bacteria
 Initially used by bacteria to cut up the DNA of virus
before it can reproduce, (Recall: Viruses are packages
of DNA that take over a cell’s machinery-in this case
for replication/transcription/translation)
 Now used by genetic engineers to cut DNA at a
specific base sequence:
o Example: EcoRI cuts DNA at GAATTC
o Example: Bam HI: GGATCC
o Example: Hae III: GGCC
 Recombinant DNA:
o Fragments of DNA cut with restriction enzymes
have sticky ends (unpaired nucleotides that are
exposed)
o The host DNA and the gene to be cloned are cut
with the same restriction enzyme so they have
complimentary base pairs
o When mixed together, the complimentary base
pairs will align creating DNA from two sources.
o Enzyme DNA ligase seals the fragments together
Ok…so you have integrated your gene into the bacterial
plasmid (circular DNA) with the cell…how do you mass
produce for industry???
PCR: Polymerase Chain Reaction (uses the process of
replication)
1. DNA is heated to 95˚ C to separate the strands of
DNA
2. DNA is cooled to 50˚ C and primers (20 nucleotide
sequence to start the process) attach
3. Temperature is raised to 70˚ C so the polymerase will
attach & copy the strand
4. DNA replication process repeats itself as the solution
is heated and cooled at regular intervals.
Ok…so you have mass produced…how do you separate the
strands?
Gel Electrophoresis (uses the principles of mass and
charge to separate)
1. The fragments are placed in wells on a sheet of gelatin
and an electric current is applied.
2. DNA is negatively charged and will move to the
positive pole.
3. Smallest fragments will move the fastest due to size.
4. Bands will be produced on the gel where the
fragments accumulate
5. Bands are stained to become visible.