DNA is the blueprint for life. This simple experiment will show you how to extract DNA from fruit like a banana or strawberry. All you need are some fruit and some things you probably have around the house right now.
What you need:
- Half of a banana, kiwi, or strawberry
- Coffee filter
- 4 tsp. 91% isopropyl alcohol – chilled
- 2-3 pinches of salt
- 2 tsp. clear shampoo
- Eye dropper
- 3 plastic cups
- Small test tube or glass
Before you start:
A blue print is a detailed drawing or map that directs the construction of a building. DNA (deoxyribonucleic acid) is the hereditary material that directs the construction of living things. Nearly every cell in a person’s body has the same DNA.
What to do:
- Mix shampoo, salt and 4 tsp of tap water. Try not to create bubbles.
- In a separate cup, mash the fruit and a little water into a pulp.
- Add 4 tsp. of fruit mush to shampoo/salt mixture. Gently mix until it is a uniform consistency. Try not to make too many bubbles.
- Place the coffee filter in a cup then carefully pour the shampoo/fruit mixture into filter. Filter until there is about 2 tsp of fluid in the cup.
- Pour alcohol into small glass or test tube. Using the eye dropper, pick up filtered fruit fluid and slowly drop it into the container of alcohol. Don’t shake it! Observe the DNA that appears.
CONGRATULATIONS! You have isolated DNA, the blueprint for all things living.
How it works:
The shampoo breaks up the membranes of the cell, allowing the DNA to come out of the cell. Filtering the fruit “goo” gets rid of the debris you don’t need. The salt can dissolve in water, but not in alcohol. In the fruit “goo”, the salt binds to the DNA and when put into the alcohol the salt solidifies and can be seen with the DNA. The salt falls to the bottom of the test tube, leaving only the DNA. The alcohol is kept cold because it helps protect the DNA.