-
Using a plastic fork, crush one banana thoroughly and mix it with ½ cup of water in a beaker
-
Mix 1 teaspoon of soap with ¼ teaspoon of salt in a plastic cup. Add 2 tablespoons of water. Stir gently to avoid creating foam. Continue for a few minutes until the soap and salt are dissolved.
-
Add 2 tablespoons of the banana mixture to the cup containing the soap solution. Use a spoon to stir the mixture for at least 10 minutes.
-
Insert a filter into a clean plastic cup so it does not touch the bottom of the cup.
-
Pour the mixture from step 3 into the filter. After 10 minutes, some liquid, called the filtrate, should have collected in the bottom of the cup. Remove the filter and set it aside.
-
Get a test tube of cold alcohol. Use a pipette to collect the filtrate and add it to the alcohol.
-
Let the test tube with the alcohol and filtrate sit undisturbed for a few minutes. The white material coming out of solution as a precipitate is DNA.
-
Dip the applicator stick into the tube, slowly rotating to spool out the banana's DNA.