1. MacGyvering Gel Electrophoresis: a Research-based Lab
Lacey Howard
Shearer Lab Research Group
Sumrall High School Biology I Students
Sorrell: 1st block 30, 3rd block 20
Hummell: 3rd block 21

2. 5 E’s of the Lesson Plan
Engage- ask students to discuss their knowledge of gel electrophoresis.
Explore- have the students practice using pipettors with a scale and water.
Elaborate- have the students perform their own gel electrophoresis experiment.
Explain- discuss the principles of gel electrophoresis and how it is used in my research.
Evaluate- have the students fill out lab worksheets with data results and summary questions.

3. State and National Subject Content
Science as Inquiry
Using the scientific method
Science and Technology
Distinguish and explain the applications of various tools and techniques used in DNA manipulation
Steps in genetic engineering experiments
Use of restriction enzymes
Science in Personal and Social Perspectives
Explain uses of technology in paternity testing and crime scene evaluations.
Unifying Concepts and Processes

4. Materials Required Each gel electrophoresis kit needs:
Five 9 V batteries connected in series
Two alligator clips with one red wire and one black wire
Small Tupperware with two holes on either end
Two wires bent through holes in Tupperware and connected to alligator clips

5. Additional Materials
1X TAE buffer (Tris base, Acetic acid, EDTA) or 1x TBE buffer (Tris base, Borate, EDTA)
Agarose
Loading Dye
Ethidium Bromide
Safety glasses
UV light
Surgical gloves
DNA
Erlenmeyer flask
Microwave

6. What is gel electrophoresis?
Gel electrophoresis is a technique that separates pieces of DNA (or other biological molecules) by size so researchers can analyze them.

7. How does gel electrophoresis work?
- Electrode
Wells for DNA samples
- Electrode
+ Electrode
Side View
+ Electrode
Top View

8. Agarose gel with Ethidium Bromide Staining
DNA Ladder
Larger DNA Fragments
Smaller DNA Fragments

9. Molecular Weight Marker
A mixture of different pieces of DNA of known size used to determine the size of fragments in the sample.

10. Staining DNA in the gel is invisible.
To visualize DNA, gels are stained with ethidium bromide.
A UV light is then used to visualize the EtBr.
CAUTIONS:
Ethidium Bromide is a carcinogen.
wear gloves
correct disposal
UV light damages eyes
wear goggles
use photoimaging system

11. Ethidium bromide
Ethidium bromide has a ring structure similar to the ring structure in DNA bases; therefore it intercolates between the bases.
Shining UV light on ethidium bromide will cause it to fluoresce at visible wavelengths.

12. Loading Dye Purposes Components give color to sample
give weight to sample so it will sink into well
show progress of gel migration
Components
dyes (xylene cyanol, bromphenol blue,
Orange G) weight (glycerol or ficoll)

13. Uses of DNA Gel Electrophoresis
Is DNA present in sample?
Is a PCR product present?
Is the PCR product the correct size?
Where in the DNA do specific enzymes cut?
Also, a specific DNA fragment can be recovered from the gel.

14. Gel Electrophoresis Start to Finnish

15. Biology I Students Performing Electrophoresis

16. Changes for the Future
This lab requires at least an hour of preparation time.
To minimize the time students are waiting for the experiment to run without having work to do, give the lecture while the experiment is running.
Explain more about PCR and restriction enzymes during the lecture.
Engage students by talking about processes they see on crime scene shows like paternity testing and DNA evidence.
Go over proper pipetting technique and aseptic technique before lab experiment.

17. References
Desktop electrophoresis lab- moving molecules
DNA gel electrophoresis

18. Q & A