Agarose Gel Electrophoresis with Food Color - Student Handout

Agarose gel electrophoresis can resolve molecules based on charge, size, and shape. In this laboratory you will use gel electrophoresis to separate molecules present in different food color mixtures.

Materials and Equipment

For each team (four individuals):

Micropipetes and tips to load dye samples.
Various dye mixtures in microcentrifuge tubes:
1. Green
2. Blue
3. Red
4. Yellow

For the class:

Electrophoresis units and power supplies
0.8% agarose in 1X TAE (melted)
1X TAE for electrophoresis units
Hot water bath to keep the agarose melted

Preparing the agarose gel

1. Record your electrophoresis unit number on your data sheet. Set up black casting dams and place a comb in the middle slot.
   
2. Pour agarose into gel deck. Pour until the gel comes close to the top of the gel deck, but do not overfill.
   
   
3. Wait for the agarose gel to solidify.
   
   
4. Remove black casting dams, add 1X TAE to electrophoresis unit, and remove comb.
   
   

Loading the samples

1. Record on data sheet where you will load the dye samples (R,Y,G,B).
   
   
2. Load the numbered dye samples in the wells in the middle of the gel.
   
   
3. Connect electrophoresis unit to power supply (red to red, black to black). Plug in the power supply.
   
   
4. Turn on the power supply, and set voltage to ~100 V. The dyes will start resolving toward both the negative and positive poles
   
   
5. Electrophorese samples for ~10 minutes. Turn off power supply, disconnect power cords from the chamber, and remove top of electrophoresis chamber.
   
   

Analyzing the gel

1. Carefully remove casting tray with gel. Place gel in large weigh tray.
   
   
2. Draw a diagram on your gel sheet of the banding pattern of the samples.
   
   

Questions

1. Which food color samples have a positive charge? Which food color samples have a negative charge?
   
   
   
   
   
   
2. What colored dyes make up each of the food color samples?
   
   
   
   
   
   

   DATASHEET

   Link to the Worksheet/Datasheet for the Electrophoresis Dyes lab

   
   
   
   

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   BIOTECH Project Department of Molecular and Cellular Biology The University of Arizona August 3, 1998 Designed by: Ken Kubo, Ph.D. Last modified March 1, 2002 Nadja Anderson, Ph.D. nadja@email.arizona.edu http://biotech.biology.arizona.edu