Detective Academy: Challenge 2

The Challenge

Use items that can be found around your house to extract DNA from a strawberry!

Looking for the Detective Academy answers from Week 1? Find them here

DNA Broken Down

 Before we get started, let’s talk about DNA.

 DNA is an abbreviation used for Deoxyribonucleic Acid. DNA is in all of us – and it’s what makes all  of us unique. It has a hand in what colour your hair and eyes are, and even the size and shape of your face!

Below is a awesome video that explains further!

Materials needed:

  • Cup, jar, bowl (something to mix a mixture in)
  • Strawberry
  • Water
  • Dish soap (unscented dish soap works the best)
  • Salt
  • Plastic sandwich bag
  • Strainer or coffee filter
  • Bowl or cup
  • Isopropyl alcohol (will need to be cold for the experiment)


Tip before we start – the more strawberries you add, the more DNA you will find at the end of the experiment.

Step 1: Before we get into the nitty gritty of the experiment, let’s put our isopropyl alcohol in the fridge to let it get cold.

Step 2: We'll begin by preparing our mixture. First, measure out 60ml of water and add it to your cup.

Step 3: Then, add 2 tsp of the dish soap into the cup full of water.

Step 4: Next, add ¼ tsp of salt to the water and dish soap mixture. Once added, stir them all together until the salt has dissolved in the mixture.

Step 5: Place the mixture to the side for a moment. Now, it is time to put our strawberry/strawberries into a plastic sandwich bag. Make sure that the strawberry stem and strawberry leaves have been removed!

Step 6: Next, add the mixture from your cup into the bag with your strawberries.

Step 7: Now, seal the sandwich bag. Make sure as you do that all the air is out of the bag Now, begin to gently crush the strawberries with your hand. Make sure that there are no large pieces of strawberry left in the bag.

Step 8: Finally, place your filter over the top of an empty cup and secure it with an elastic band. Then, begin to empty the contents of the bag through the filter and into the cup.

Step 9: Now that everything is strained through it is time to take our isopropyl alcohol out of the fridge and add 1-3 tsp of isopropyl alcohol into the strained mixture. (You'll start to see the DNA showing up as you add the alcohol. If you aren't seeing much after the first or second tsp, add another).

Final Product: Once the isopropyl alcohol is added to the mixture there should be a white film that begins to show up at the top of the mixture. The white film is the strawberry’s DNA!

Want to learn more about DNA?

Check out ScienceFlix

Our science database for grades 4-6 walks you through 30 science topics, relating to science, technology, and engineering. Watch videos, read articles, and do experiments!

Answers for Week 1

Who am I?

  1. Piano
  2. Clock
  3. Apple
  4. Sun
  5. Balloon
  6. Tree
  7. Star
  8. Telephone
  9. Book
  10. Coin


  1. Your name
  2. An egg
  3. A window
  4. Second place
  5. Table or chair
  6. A cold
  7. A book
  8. The library
  9. A coat of paint
  10. You have two apples

Looking for more?

Our blog is brimming with ideas and activities that will keep you busy through the summer. 

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