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Lesson 6: Electrophoresis Protocols

Purpose: This lesson familiarizes students with the technique of pouring and loading an agarose gel through a teacher demonstration.

Time: One 50-60 minute class period

Materials Preparation:

• 100X electrophoresis buffer stock
• Deionized water
• 100 ml and 1000 ml graduated cylinders
• Methylene blue concentrate
• Centigram balance
• Agarose
• Large test tubes
• Casting trays with combs and glass plates
• Masking tape
• Plastic pipettes
• Boiling water bath

Student Objective(s):

• Explain how an agarose gel is poured and DNA is loaded into the wells of the gel.

Lesson Plan:

(1) Hand out the reading material "Electrophoresis Protocols".

(2) Discuss each step described by demonstrating the preparation of the electrophoresis buffer, the methylene blue dye, and the agarose solution. Pour an agarose gel and while it is cooling, hand out the assignment "Gel Electrophoresis and Analysis".

(3) Have the students work in class on this assignment until the gel is cooled (about 10-15 minutes before the end of class). When the gel is cool, place it into the electrophoresis chamber, cover the gel with buffer and then load a "DNA sample" into one of the wells. Invite students to practice loading "DNA" into the wells. (Use loading dye to simulate DNA).

Supporting Materials:

• "Gel Electrophoresis Protocols" - Directions
• "Gel Electrophoresis and Analysis" - Lab Sheet
• "Gel Electrophoresis and Analysis" - Answer Key
  

The University of Arizona
Department of Biochemistry and Molecular Biophysics
General Biology Program for Secondary Teachers
warder@email.arizona.edu