Cockrell School of Engineering
Biomedical Engineering

DNA Extraction Extravaganza

Presented by UT Austin's Women in Biomedical Engineering
Age group: Elementary School, Middle/Junior High School

Ever wondered why you look similar to your parents, siblings, cousins, or grandparents? Ever wondered what makes you unique? Ever wondered what makes something living? The answer to all of those questions is deoxyribonucleic acid or DNA.  DNA is the material that carries all the information for how a living thing will look and function. For humans, DNA will determine your eye color, hair color, and other physical traits. Today, you'll be learning a bit more about yourself and the world around you by extracting DNA from fruits.


The Challenge: Successfully extract DNA from fruit of your choosing (strawberry, banana, kiwi, etc.)

You'll need the following materials: • fruit of your choice • 1/2 cup of water • 2 small plastic cups • 2 teaspoons of dish soap • 2 teaspoons of salt • 1 coffee filter • 1/3 cup of rubbing alcohol • 1 plastic bag • 1 plastic spoon

Here's what you need to do:

1. Add 2 teaspoons of dish soap in 1 plastic cup. Slowly mix in 1 teaspoon of salt. Then, mix in 1/2 cup of water.
2. Add 1/4 cup of your fruit into 1 plastic bag. Mash up the fruit with your hands until there are no big chunks. Add 2 tablespoons of the mixture from step 1 into the plastic bag. Gently swirl with a plastic spoon for 1 minute and then let it rest.
3. Cover an unused plastic cup with the coffee filter. Slowly pour the plastic bag mixture over the cup and let it filter for 30 seconds or until the fluid has stopped dripping.
4. Pour 1/3 cup of cold rubbing alcohol down the side of the cup. Do not mix or stir.
5. Within a few seconds, watch for the development of a white cloudy substance (fruit DNA) in the top layer above the fruit layer.
6. Tilt the cup and pick up the fruit DNA with the plastic spoon.

Congratulations! You've successfully extracted DNA from a fruit!

Presented by UT Austin's Women in Biomedical Engineering (WBME)