Camp Yellow Scope: Strawberry DNA

Howdy Campers!

Welcome back to Camp Yellow Scope. We hope you enjoyed last two weeks learning about detergents, dyes and drops! Are you ready to have some more fun with detergents? It's week 3 of Camp Yellow Scope: Strawberry DNA!

Click here to download printable instructions for the experiments. You can also print out a lab worksheet to record your observations, jot down ideas, and design your own experiments! If you collect your worksheets together from all eight weeks, by the end of the summer you will have your very own Camp Yellow Scope notebook! You can even add some extra sheets for new experiments you design yourself.

Experiment 1: Strawberries & Strands

You may have heard of genes and DNA. DNA is found inside the cells of all living things – from humans to guinea pigs, and fungus to strawberries. DNA contains the instructions to make living things.

But have you ever seen DNA? Well today is your lucky day! And you don’t need to visit a fancy science lab - you can isolate DNA right at home. How cool is that?! In the first two weeks of Camp Yellow Scope, you used detergents to paint on milk and to destroy water drops. Now you'll use detergent to isolate DNA from strawberries. (And you thought dish soap was just for washing dishes...!)

Let’s get started!

Clear a space on the kitchen counter, your desk, or the picnic table in the backyard. Put on some clothes that can get messy, and get ready to pull the DNA out of strawberries!

Hypothesis

What do you think will happen when you mix dish soap with strawberries? Record your hypotheses on your lab worksheet.

 Instructions                         

1. Put the rubbing alcohol in the freezer to chill. You'll use it later.  Warning: Rubbing alcohol should only be handled by an adult.
2. Make the DNA Isolation Solution (see sticky note)
3. Remove the green top from the strawberry. Place the strawberry in the baggie.
4. Add 2 tablespoons of the DNA isolation solution to the baggie with the strawberry.
5. Carefully push the air out of the baggie and seal it tightly.
6. Use your fingers to squeeze, smash, and mush the strawberry in the extraction solution until there are no large pieces left.
7. Place the sieve over the small glass or jar.
8. Pour the strawberry mixture from the bag into the sieve.
9. Once all the liquid has drained through (you can gently push on the strawberry pulp with the back of a spoon to help it drain), set the sieve aside and discard the leftover strawberry material.
10. Tilt the glass or jar containing the strawberry liquid, and very slowly pour 1 tablespoon of ice cold rubbing alcohol down the side of the glass. The alcohol should form a layer on top of the strawberry liquid. Be careful not to mix the two layers.
11. The DNA will collect at the interface between the two layers (the place where the two layers touch). It will look like stringy, gooey, white strands. Look through the side of the glass to see strands of DNA in the strawberry liquid.
12. To collect the DNA, carefully dip the bamboo skewer or toothpick into the alcohol layer and swirl around the interface. Carefully pull out the skewer or toothpick and check it out up close!

What’s happening?

Each part of the DNA isolation solution plays an important role in pulling the DNA out of the strawberry.

• Dish soap: The detergent helps to dissolve and break open the membranes of the strawberry cells.
• Salt: Salt helps to break up the cellular proteins that surround the DNA to release the DNA strands.
• Rubbing alcohol: Because DNA is not soluble in the alcohol, it clumps together, or precipitates, in the alcohol.

Why does it matter?

Can you think of real world examples where isolating DNA is important

?

• At crime scenes, scientists isolate DNA from blood or hair samples to identify victims and criminals. This branch of science is called forensic science.
• Paleontologists isolate DNA from ancient human, animal, or plant samples to identify and characterize species.
• Doctors isolate DNA to detect genetic diseases.

You own it!

Test yourself: true or false

1. Dish soap helps dissolve and break open cell membranes during DNA isolation.
2. Doctors have no use for isolated DNA.
3. DNA is soluble in alcohol.

Answer Key:
1. True.
2. False. Doctors isolate DNA to analyze for genetic diseases.
3. False. DNA is not soluble in alcohol, so it clumps together and precipitates out.

We hope you had fun learning about DNA and isolating it from a strawberry! Next week at Camp Yellow Scope, we’ll explore celery and its built-in straws! Intrigued? Check back next Tuesday for new experiments and more summer science fun!

We'd love to see how your experiments turned out! How much DNA did you pull out of the strawberries? Share your photos or videos: 

• Facebook: Yellow Scope Science Kits for Girls
• Twitter: @YellowScopeGirl, #CampYellowScope
• email: info@yellow-scope.com

For more exciting experiments, check out our science kits on the SHOP tab of our website!