Download DNA Extraction KEY

Name:_______________________________________________________Period:___________Score:________
Teacher’s Initials _______________
Analysis Questions
1. The DNA extraction buffer is made up of detergent and salt. Why is there detergent in the buffer?
Break down the cell walls/ membranes.
2. What is the purpose of the salt found in extraction buffer?
adds positive charge and neutralizes the negative charge of the DNA that is a result of the phosphate backbone
3. What does the alcohol do? Why does the DNA rise to the top after adding alcohol?
DNA is insoluble in alcohol—separates.
It is less dense than the alcohol.
4. What do you think might happen if alcohol was added quickly and the two layers mixed?
The DNA wouldn’t separate as easily—would have to wait.
5. Describe the appearance of the DNA you extracted (color, shape, texture, consistency).
Color- clear; shape-tubular; texture- _____; consistency-_______
6. Where is the DNA found in a cell?
Nucleus
7. What fruit did you use to extract DNA?
8. Does the amount of DNA differ when extracted from different fruits, fresh vs frozen??
To answer this, you will want to compare your DNA sample to someone else’s?
If there is a difference, list the top 3 fruits that yield the most DNA.
Fresh Strawberry
Frozen Strawberry
FYI: If you want to do this at home, here is the buffer recipe.
DNA Extraction Buffer: Enough for 100 strawberries
100 mL (3/8 cup) liquid dishwashing soap or shampoo (without conditioner)
15 grams (2 teaspoons) salt
900 mL (3 3/4 cups) water
Name:_______________________________________________________Period:___________Score:________
9. Do you think there would be a difference between using vegetables instead of fruit in the experiment? Explain.
Yes, different amount of DNA.
10. In what real-life situation would the extraction of DNA be useful? Explain.
Dead bodies, Forensic science, analyze DNA for disease, baby daddy?
FYI: If you want to do this at home, here is the buffer recipe.
DNA Extraction Buffer: Enough for 100 strawberries
100 mL (3/8 cup) liquid dishwashing soap or shampoo (without conditioner)
15 grams (2 teaspoons) salt
900 mL (3 3/4 cups) water