By Katrina Arthurs | Updated Mar 24, 2022
Deoxyribonucleic acid (DNA) is the genetic blueprint that defines every living organism—from humans and animals to microbes and fruit. With just a few everyday kitchen supplies, you can isolate DNA from an orange and witness the double‑helix in action. This experiment is safe for classrooms, science clubs, or curious students at home.
Fill a cup with rubbing alcohol and place it in the freezer for at least 30 minutes before you begin.
Peel the orange and cut it into small pieces. This increases the surface area and helps release the DNA.
Place the orange pieces in a blender. Add warm water and a teaspoon of salt. Blend until you have a thick, pourable liquid.
Position a coffee filter over a glass jar. Pour the orange mixture into the filter until the jar is about half full. Remove the filter to keep the liquid in the jar.
Stir in two teaspoons of liquid dish soap, being careful to avoid bubbles. The soap helps to break down cell membranes, releasing DNA into the solution.
Retrieve the chilled alcohol from the freezer. Slowly pour it into the orange mixture along the side of the jar, creating a thin, separate layer on top. Do not pour directly into the center. This alcohol layer will pull the DNA out of the aqueous solution.
Let the mixture stand undisturbed for about 10 minutes. During this time, DNA strands coalesce and rise to the top of the alcohol, forming a white, stringy mass.
Use a toothpick or a sterile stirrer to collect the DNA strands and observe their characteristic filamentous structure.
