The Abstract
Today we're setting up the science behind Thursday's experiment. We'll talk about what DNA is, where to find it, and prepare you for what your kids will see when they extract it from a strawberry.
The PhD Deep Dive
DNA is the instruction manual inside every living cell, written in a chemical code that determines how organisms grow, function, and reproduce.
Strawberries are octoploids - they have eight copies of their DNA compared to the two that humans have, which makes the extraction visually dramatic and easier for kids to see.
The experiment uses freezing and dish soap to break open cell membranes, salt to precipitate proteins, and cold alcohol to make the DNA clump together into visible white strands.
This same basic technique - cell lysis, protein removal, and DNA precipitation - is used in genetic engineering, forensic science, and medical diagnostics.
The Big Picture
DNA is a physical, extractable molecule (not just an abstract concept) that is foundational to scientific literacy in the 21st century. The researchers developing mRNA vaccines, engineering drought-resistant crops, and personalizing cancer treatments are all manipulating the same molecule your kid will hold on a popsicle stick Thursday morning.
The Dinner Table Toolkit
Vocab Words
DNA (deoxyribonucleic acid): This is the tiny, twisted ladder inside your body that holds all the secret instructions for making you who you are.
Genetic: This describes traits, like the color of your eyes or the shape of your nose, that are passed down to you from your parents.
Fun Fact to Share
Strawberries have eight copies of their genetic information (compared to humans who have just two copies), plus they’re soft and packed with cells - which is why this experiment works so well and you can actually see the DNA!
The Debate Question
If scientists can read the “instruction book” for a strawberry, should they be allowed to rewrite parts of the instruction book to create better strawberries? How would you improve a strawberry, if you could?
The company JR Simplot has used modern genetic modification tools to create strawberry plants that will yield more on less land and strawberries that will last longer on store shelves before going bad. How cool is that?!?
Parent-to-Parent Note
Engagement Ratings
This was a high-interest lab for ALL my kids aged 6-13. My 6-year-old didn’t understand all the concepts but he was totally into the whole activity. I couldn’t get him to stop talking about DNA!
Safety Tip
Isopropyl alcohol is flammable; please keep it away from heat or open flames in the kitchen.
Prep for Thursday
Materials
2-3 Frozen strawberries, 1/2 cup water, 1 tbsp dish soap, and 1 tsp salt, ¼ cup ice-cold rubbing alcohol (70% or 91%)
Equipment
1 ziplock bag, 1 medium or large bowl, 1 colander (should nest inside of bowl), 1 circular coffee filter or large paper towel, 2 clear and colorless plastic or glass cups, 2 popsicle sticks
Do Before Thursday
Freeze your strawberries tonight (if using fresh)
Freeze the rubbing alcohol tonight - it needs to be ice-cold for the DNA to precipitate properly
Questions?
Questions before, during, or after Thursday’s experiment? Reach me at labcoatandlegos@gmail.com or drop a note in the Substack chat and I’ll get back to you.
