Assignment: After participating in the classroom dramatization of the process of gel electrophoresis and the post-activity discussion, answer the following questions.

1. What is the function of each of the following in gel electrophoresis of DNA?

• Agarose gel:
  
  
  
• Electric current:
  
  
  
• "Wells" in the gel:
  
  
  
  

2. Toward which pole (positive or negative) does DNA migrate when electric current is run through the gel? _____________ Why do the DNA molecules move toward this pole?

3. What would happen to the DNA fragments if you forgot to turn the current off?

4. Describe how different sized DNA fragments are separated by the gel matrix.

5. Examine the diagram of an agarose gel below and answer the following questions.

• What do the bands in the drawing of the agarose gel represent?
  
  
  
• Which band(s) traveled slowest?
  
  
  
• Which band(s) traveled fastest?
  
  
  
• On the above drawing, label the positive and negative ends of the gel.
  
  
  
• How many bands are shared in common by all of the individuals?
  
  
  
• Are there any bands which are unique to only one individual? ____ If so, which one?
  
  
  
  
  

Science Education Connection Department of Biochemistry The University of Arizona May 1, 1997 warder@u.arizona.edu http://biology.arizona.edu/sciconn/lessons/alongi/ All contents copyright ©1997. All rights reserved.