DNA Extraction Lab
Purpose: The purpose of this demonstration is to isolate the DNA that is in your body.
Materials: Meat Tenderizer, Salt Solution, Gatorade (Salt Water), Dishwashing Detergent (Grease fighting), Ethanol
Alcohol, Ice Bath, Dixie Cup, Toothpick, Beaker of Water.
Pre-Lab: (Bellringer)
1.
Illustrate a basic drawing of an animal cell. Be sure to label the following: cell membrane, nucleus, nuclear
membrane, DNA.
2.
How is DNA stored in the cell?
3.
What will have to happen to the cell before the DNA can be removed?
4.
What happens to proteins if the temperature gets too hot?
Procedure:
1. Run your teeth over the inside of your cheek but DO NOT bite. Drawing blood will hurt and ruin your
experiment.
2. Put Gatorade (salt water) in your mouth and swish for 1 minute.
3. Spit the contents of your mouth back into your cup.
4. Add one drop of soap to your cup.
5. Dip your toothpick into the beaker of water, only getting a drop on the tip of the toothpick.
6. Put the toothpick in meat tenderizer.
7. Put the meat tenderizer into the sample cup by twirling the toothpick. DO NOT STIR THE CONTENTS!!!
8. Pour 5 mL of your sample into a 15 mL test tube.
9. Add 5 mL of the ice cold Ethanol to the test tube very slowly. Allow the Ethanol to run down the side of the test
tube so it will gently mix with the sample solution.
10. The DNA should separate into a gelatinous substance. You may extract your DNA from the test tube.
Analysis Questions:
1.
In terms of tonicity, why do we use salt water or Gatorade to collect our cells?
2.
Based on what you know about the composition of the cell membrane, why would you need to add GREASE
FIGHTING DETERGENT to your sample?
3.
Based on what you have learned about enzymatic reactions, describe the purpose of the meat tenderizer
(protease-enzymes that break down proteins or polypeptide chains).
4.
What significance does the temperature of the Ethanol play in the extraction of the DNA? Explain your
reasoning.
5.
Illustrate your findings from your DNA Extraction.