A strawberry DNA extraction is the closest most of us will ever get to holding the molecule of life in our hands. In about 20 minutes, with dish soap, salt, and rubbing alcohol from the medicine cabinet, you can pull visible white strands of DNA out of a strawberry and wind them onto a skewer.

Universities and research institutes use this exact activity to introduce molecular biology, and it’s just as rewarding for adults who never got to try it in school. It’s a good fit for the 25Pages way of learning: predict, test, explain.

Make a prediction first

Write down your answers before you start. What color do you think DNA will be? Will you need a microscope to see it? Would a banana or a kiwi give you more DNA than a strawberry, or less?

What you need

This list follows the Science Buddies home version:

• 3 strawberries, tops removed
• ½ cup rubbing alcohol, chilled in the freezer until very cold
• ⅓ cup water, ½ teaspoon salt, and 1 tablespoon dishwashing liquid
• A resealable sandwich bag
• A funnel lined with cheesecloth (a coffee filter also works), and a tall glass
• A small clear jar, such as a spice jar
• A bamboo skewer or toothpick

Step-by-step

1. Chill the alcohol. Put the rubbing alcohol in the freezer first. It needs to be very cold.
2. Make the extraction liquid. Mix ⅓ cup water, ½ teaspoon salt, and 1 tablespoon dishwashing liquid. Stir gently so it doesn’t foam too much.
3. Mash the strawberries. Seal the strawberries in the bag with the air pushed out and squeeze them with your fingers for 2 minutes. The University of Queensland’s Institute for Molecular Bioscience advises mashing by hand rather than hitting the bag on a table, which can damage the DNA.
4. Add the extraction liquid. Add 3 tablespoons, reseal, and squeeze gently for another minute.
5. Filter. Pour the mixture through the lined funnel into the tall glass and let it drip until only wet pulp remains.
6. Layer the alcohol. Fill the small jar about ¼ full with the filtered liquid. Tilt the jar and pour the cold alcohol very slowly down the side until it forms a layer about an inch deep on top. Don’t let the two layers mix.
7. Watch and spool. Within a minute or two, white, cloudy, gooey strands should appear where the layers meet. Dip the skewer into that boundary and twist slowly to wind up the DNA.

What each ingredient does

• Dish soap breaks open, or lyses, the strawberry’s cells, releasing the DNA into the liquid, according to Science Buddies. Cell membranes are made of fats, and soap breaks up fats, just as it does on a greasy pan.
• Salt helps the DNA strands clump together so they’re easier to see. The University of Queensland also notes it helps keep the cell’s proteins separate from the DNA.
• Cold alcohol: DNA doesn’t dissolve in alcohol. At the boundary it comes out of solution and clumps together, a process called precipitation. That makes it visible to the naked eye.

Why strawberries work so well

Humans carry two copies of each chromosome. Grocery-store strawberries carry eight. They’re octoploid, which is why they yield far more DNA than most other fruits, the Carl R. Woese Institute for Genomic Biology at the University of Illinois explains. LaGuardia Community College’s biology lab guide adds a nice detail: the wild woodland strawberry has only two sets of chromosomes. The extra copies came with the hybrid garden strawberry we buy today.

One more thing to remember: a single DNA molecule is far too thin to see. What you’re spooling is millions of strands clumped together, which is the only reason you can see it at all.

Turn it into an experiment

• Compare fruits: repeat with a banana or kiwi and compare how much DNA you get. Use your prediction from the start.
• Test one variable: leave out the salt, or use room-temperature alcohol, and see what changes.
• Design your own protocol: the Fred Hutch Cancer Center’s science education program challenges students to design their own extraction protocol and refine it as a group. That’s a great model for a book club or family science night.

Safety notes

• Rubbing alcohol is flammable. Keep it away from stoves, candles, and any open flame, and work in a ventilated room.
• Don’t drink or taste anything in this experiment, including the strawberry mixture once soap is added.
• Wear safety glasses when pouring alcohol, and rinse with water if any splashes in your eyes or on skin.
• Pour leftover liquids down the drain with plenty of water, cap the alcohol, and wash your hands afterward.

Check your prediction

Was the DNA the color you expected? Did you need a microscope? Can you explain to someone else why soap, salt, and alcohol each matter? If so, you’ve mastered the core idea behind one of the most important techniques in modern biology.

Keep learning, one idea at a time

If you enjoy science at this depth, The Chronicle MMXXVI Editor’s Edition ($480) is the 25Pages annual hardback for lifelong learners, and The Chronicle 2026 Vol. I Standard Edition is $347. For more hands-on projects, explore the DIY Blue Book of Experiments MMXXVI ($480), or browse everything at 25Pages.com.