Gel ElectrophoresisBy: Grace Forster and Ashlyn Cowan

a process that seperates large molecules (including nucleic acids or proteins) by size, electric charge, and physical properties

Invented in 1975 by Fred Sanger

What is it?

Seperates by:◦ Charge

The negatively charged DNA moves towards the positively charged end of the gel

◦ Size The larger the particles the less far they are able to

travel through the gel◦ Physical properties

Different shapes and qualities affects how certain DNA move through the gel

How it works:

1. Permeable gel with a row of holes on one side is filled with DNA samples

2. An electric current is sent through the gel1. The DNA is negativly charged so it moves towards the

positively charged opposite end

3. The larger DNA fragments cannot travel as far through the gel, so bands are formed where the fragments stop

1. Staining the DNA with methylene blue allows us to see bands with naked eye or else we must look at them under UV light after staining them with ethidium bromide

4. These bands can be used to compare DNA similarityhttp://learn.genetics.utah.edu/content/labs/gel/

Process:

This is an agarose gelthat you mix together and cast by baking it in an oven and then letting it cool.

Once cooled one usesA comb-like structure to make the holes.

1. Create Gel

Use pipette to carefully fill the holes with each specific DNA

Fill holes with DNA

Place gel in tray filled with a buffer covering the gel◦ The negative electrode attaches to the end near

the holes holding the DNA◦ The positive end attaches toward the opposite

end to attract the negatively charged phosphate groups of the DNA

Electrodes are attached to power supply and turned on

Once DNA has moved through gel, turn off power supply

Send electric current through gel

Stain the gel with Methylene blue to see it with the naked eye

or Stain the gel with ethidium bromide which

binds to the DNA and flouresces in the UV light

Staining the DNA

DNA profiling using ◦ probes ◦ PCR

Gene analysis

What we use it for: