Genetic Engineering (and other cool molecular biology techniques)
Post on 22-Mar-2016
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Genetic Engineering (and other cool molecular biology techniques)
DNA Cloning• DNA cloning permits production of multiple
copies of one particular gene • This gene copy will be used to produce a usable
protein product (e.g. insulin) or for genetic engineering (e.g. gene for pest control inserted into plant)
For Fun:
• We want to clone a gene that produces a protein that will help you focus while studying.
1. We need the gene• This gene is located on chromosome 16
2. We need a vector• Vector – a DNA molecule (usually a bacterial
plasmid) that is specifically designed to carry foreign DNA– Selectable marker– MCS
3. Restriction Enzymes
• Restriction Enzymes – cut DNA at particular sequences – Ex: EcoR1 – recognizes GAATTC– 100’s of RE’s
Transformation• Get “competent” bacteria
(usually E.coli that is capable of being transformed)
• Treat those cells to calcium chloride
• Heat shock to force bacterial cell to take up plasmid DNA
Now…• Select for bacteria
that have taken up your plasmid (usually use antibiotic)
• Grow bacteria in large quantities, purify out protein, and…
PCR (polymerase chain reaction)
• Specific sequence of DNA is amplified (copied many times)
• Requires: – DNA template (contains your gene of interest)– Tac polymerase (a DNA polymerase that can work
at high temperatures)– Nucleotides (to synthesize new DNA)– Primers (specific to the gene of interest)
• PCR is a cyclic process:– Heat to denature
(open up) DNA– Cool to allow primers
to anneal (stick to) single stranded DNA
– Warm to allow DNA to be replicated by polymerase
– REPEAT
Gel Electrophoresis
• Uses a gel as a molecular sieve to separate pieces of DNA based on size
• Smaller pieces travel further than larger pieces
Let’s discuss some examples
1. Genetically modified food2. Transgenic animals3. Pharmaceuticals
1. Genetically Modified Food
• Insert particular genes within a type of food to make it better tasting, longer lasting, or more healthy.
• Long term effects of consumption of this food are unknown.
2. Transgenic Animals• Research purposes– Knock outs– Overexpression – Use of GFP to select for
animals that are transgenic• Consumer purposes (food
or medication)
3. Pharmaceuticals
• Use plants or other GMO to produce pharmaceuticals– Ex: Gaucher’s disease (lysosomal storage disease – buildup
of fat in cells); Pfizer received patent to grow drug to treat this disease in tobacco plant
– Ex: Use of a transgenic goat to produce an anticoagulant (in the goat milk) to reduce probability of blood clots
• Use bacteria to produce insulin, human growth hormone, clotting factors for hemophaelics
• GMO mammals (mice) used in pharmaceutical research labs to study disease and treatment
Your Homework:
• Read the entire laboratory handout. You must carefully read the background information AND the laboratory procedure as well.
• Answer the pre-lab questions.
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