Gel Electrophoresis Electrophoresis DNA Separation Standard tool in

Gel Electrophoresis

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

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

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

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

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

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

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

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

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

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

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