Extract Pumpkin DNA

Materials you'll need

• Pumpkin, chopped into small cubes
• Water
• Measuring cup
• Blender
• Dish soap
• Table salt
• Spoon
• Fine-mesh strainer
• 2 small glasses
• Rubbing (isopropyl) alcohol, chilled in the freezer for 30 minutes
• Toothpick

 

Step-by-step tutorial

Step 1: With an adult's help, chop your pumpkin into small cubes.

Step 2: Add the pumpkin cubes to a blender along with 1/3 cup of water, and blend until smooth.

Step 3: Pour the blended pumpkin into a glass, then stir in 1 tablespoon of dish soap and 1 teaspoon of table salt until well mixed.

Step 4: Pour the mixture through a fine-mesh strainer into a clean glass, keeping just the liquid and setting the pulp aside.

Step 5: With an adult's help, slowly pour rubbing alcohol down the side of the glass so it forms a separate layer on top of the pumpkin liquid — don't stir it in! (Pro tip: pop your rubbing alcohol in the freezer for 30 minutes before you start)

Step 6: Watch closely where the two layers meet. Cloudy white strands will start to form. That's the pumpkin's DNA.

Step 7: Use a toothpick to carefully lift out and take a closer look at the DNA strands you made.

Learn more

Every living thing — including pumpkins! — keeps its genetic instructions, or DNA, tucked safely inside its cells. Dish soap works a lot like it does on a greasy dinner plate: it breaks apart the fatty membranes surrounding each cell so the DNA inside can spill out into the liquid. The salt then helps cancel out DNA's natural electric charge, so instead of staying spread out, the DNA molecules can start clumping together. Since DNA doesn't dissolve in alcohol, when that cold layer hits the pumpkin liquid, the DNA from millions of cells bunches up into the cloudy white strands you can actually see and pull out with a toothpick.