SL Biology Unit #6 Biotech
PCR DNA Profiling DNA Extraction Transgenic
Bacteria Animal Cell
Transformation
Restriction Enzymes
Gel Electrophoresis
Transgenic Plants
Cloning
DNA Extraction
Place cells in detergent to break down membranes and salt to remove the histone proteins on the DNA
Place cell extract in ethanol DNA is insoluble in
ethanol, so it comes out of solution, and can be removed for study
Polymerase Chain Reaction (PCR)
Takes a small amount of DNA, and makes many copies of it The more DNA available,
the more studies you can do with it
Frequently used for small amounts of DNA left at crime scenes
Polymerase Chain Reaction (PCR)
The DNA fragment to be copied is heated to make the strands separate.
Enzyme DNA polymerase adds new complementary strands to each old strand.
The process is then repeated over and over.
DNA Profiling
Just as no two people have the same fingerprint, no two people (except identical twins) have same DNA.
DNA Profiling
Differences between individuals are due to different sequences of nucleotide bases Remember, different alleles are
result of differences in base sequences
Ex: AACTGGCA vs.AACCGGCA
Restriction Enzymes
A restriction enzyme is an enzyme that cuts DNA into small fragments.
The size of the fragments depends on the person’s DNA sequence.
Therefore, you get different sized fragments from different individuals.
Gel Electrophoresis
Gel electrophoresis is a way of separating, by size, the DNA fragments produced by restriction enzyme cuts
Gel Electrophoresis
1.DNA fragments placed into wells in gel slab
2.Electric voltage is applied to gel.
3.DNA (negatively charged) migrates to (+) end of gel.
4.Smaller the fragment, faster and farther it moves.
Transgenic Bacteria
Genes for human proteins like insulin and blood clotting factor can be inserted into bacteria
Bacteria then translate the inserted gene to produce the protein it codes for
Proteins can be used to treat people with disorders like diabetes or hemophilia
Transgenic Bacteria
Transgenic Plants
Plants can be transformed with genes from other organisms to: Help plants resist pests Help plants resist weed-killing
chemicals Give plants additional nutrient
value
Transgenic Plants
Process uses a bacteria that infects plants and causes tumors
Tumor-causing gene is removed, and another gene of choice is inserted
Animal Cell Transformation
Uses: Insert human genes into experimental animals (mice) to study the gene function
Create livestock that grow faster, produce leaner meat, resist disease better.
Animal Cell Transformation
DNA to be inserted is injected directly into fertilized egg.
Cell enzymes that usually repair DNA or help in recombination insert the new DNA into the animal’s chromosomes.
What is cloning?
Cloning to Create a New Individual Genetically Identical
to an Existing Organism
Cloning to Create a New Individual Genetically Identical
to an Existing Organism