1. Gel Electrophoresis

2. Electrophoresis: DNA Separation
Standard tool in biochemistry labs
Uses
Diagnose disease
Identify genes and gene structures
Human genome project
Understand evolution of plants and animals
Genetic engineering of organisms (Example: drought resistant crops
Forensic science

3. DNA! Extracted from animal, plant, and bacteria cells
Individual cells are split open, and the DNA is separated from the rest of the cellular debris
DNA is then treated with special proteins called restriction enzymes, which cleave the DNA into smaller fragments

4. How does Electrophoresis work?
DNA molecules are negatively charged
Use electricity to separate DNA protein molecules based on charge and mass
DNA samples are taken from animal or plant cells

5. Agarose Gel Used as the support material to separate DNA molecules
Derived from seaweed
Note “wells”- DNA solution is loaded into these holes

6. Loading the Gel
DNA loaded into gel: mixture of different sized DNA fragments

7. Loading the Gel Loading gel with DNA mixture + dye
Gel is suspended in buffer which conducts electrical current

8. Separation of DNA
Note applied electrical charge- DNA is negatively charged and will migrate to the positive pole
Gel matrix acts as a “seive” for DNA
Large DNA molecules cannot pass through the small holes in the gel
Small molecules move easily through the gel

9. Running the Gel Electric current is applied to gel
DNA starts to migrate through the gel

10. Separation of DNA
As separation continues, the smaller fragments move farther down the gel

11. Molecular Markers
A DNA molecular marker “ladder” is run at the same time as your sample DNA
Markers are of known molecular weights
Markers used to estimate the sizes of your sample DNA

12. Reading the Gel Dye in gel reacts with UV light, DNA is fluorescent
Photo taken