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