1. Another way to separate mixtures!
Electrophoresis
Another way to separate mixtures!

2. What is gel electrophoresis?
Electro = flow of electricity
Phoresis = to carry across
A gel is a colloid—a suspension of tiny particles in a medium, occurring in a solid form…like gelatin

3. What is gel electrophoresis?
Gel Electrophoresis refers to the separation of molecules based on charge, size, and/or shape of the particles.
The charged macromolecules move through the gel because they are in an electric field.
The gel acts as a filter (like a micro obstacle course) to control the rate of movement (speed) of the particles.
Charged particles can include DNA, amino acids, peptides, etc.

4. What is needed?
Buffer—a solution that maintains a stable pH when acids or bases are added
Agarose—a polysaccharide extracted from a type of seaweed. Agarose is dissolved in buffer and is heated. It is allowed to cool into a gelatinous solid that has a network of cross- linked molecules.

5. (tris borate EDTA/trisacetate EDTA)
What is needed?
Buffer—usually TBE or TAE
(tris borate EDTA/trisacetate EDTA)
The buffer provides ions in solution to ensure electrical conductivity
The agarose is dissolved in buffer AND the finished gel is submerged in the same buffer solution

6. What is needed? Power Supply—you need electricity for electrophoresis
Gel chamber—holds the gel and the buffer; has positive and negative electrodes

7. Steps for electrophoresis…
Agarose is made to the appropriate concentration—from 0.7% agarose to 2% agarose
The higher the concentration, the ___ the gel.
The higher the % agarose, the _________ the fragments move.
The gel casting tray is set up with a comb inserted
The gel is poured and allowed to cool

8. Steps for electrophoresis…
The cooled gel is placed in the gel chamber and buffer is added to cover the gel
The comb is removed, leaving little wells in the gel
The samples are put into the wells using a micropipette
Micropipettes have disposable tips and can accurately measure to less than 1/1,000,000 of a liter

9. Steps for electrophoresis…
The power source is turned on = running the gel
Should see bubbles forming along wires/electrodes = electrolysis of water
products?????????
Time for the run depends on % gel, amount of current, and sizes of particles
At the end of the run, you look at the end result and get an image (take a picture) of the gel
Visible or UV light