Science Buddies: "Ask an Expert"

I am working on the project that extracts the DNA out of strawberries. How does the DNA get taken out of the cells and the solution? Is there a chemical reaction ? Also does this work with other fruit? Please get back to me, Thank you.

Hello,
To answer you question, think about what you add to the strawberry before you see the DNA. What do you think these component do to the cell? What barriers must the DNA cross in order to escape the cell? It must get out of the nucleus and out of the cell membrane, right?

Hope this helps get you on your way to figuring out your question. In regards to whether it will work on other fruit, yes! But see if you can determine why out of all of the different types of fruit, vegetables etc this experiment has you use a strawberry. I'm sure there's a reason.

While extracting the DNA from strawberries we use a lot of different materials. Is there a certain material thats an independent variable ? And wouldnt the stawberries be the dependent variable? Also is there other fruit or vegetables that have more than 8 copies of the genome?

Hello,
I think strawberries are the only fruit that are octoploid. (8 pairs of chromosomes) You could probably google that term and see if anything else comes up.

If you look up the definition of independent vs dependent variables you will see that all inputs into an experiment are "independent variables". Meaning that each input, so in your case, the strawberry, the soap, the alcohol all can have a separate impact to the final result. Meaning, if any one of those materials are faulty it could impact your final outcome of the experiment. The result of the experiment is the "dependent variable" because how the result turns out depends on whether the inputs work correctly. Does that make sense? For example, if your alcohol (independent variable) is the wrong concentration....suppose you use 25% instead of 90 or 100%, then you may not see the DNA precipitate at the end of your experiment. Likewise....if you forget to add salt to your soap solution, that would also impact the end result of DNA precipitating from solution. Hope this helps!

In the strawberry experiment if all the inputs are independent variables would that mean there isn't a control?

Hi,

Good questions about controls. Did you read this section about variables and controls? https://www.sciencebuddies.org/science- ... ndex.shtml

So to answer your question, I need to know if you did more than the experimental procedure, or if you changed some variables to test the outcome. If so, what controls did you use to make sure the experiment was working properly? you may have used the standard protocol in order to be sure it all works the way we expected.

I hope this helps. Tonya

Hi there,

Katie has already given you some great advice! I just wanted to point out that Science Buddies has a couple projects related to yours:
Do-It-Yourself DNA: https://www.sciencebuddies.org/science- ... p015.shtml
Extracting Onion DNA: https://www.sciencebuddies.org/science- ... p001.shtml

The information in these projects will help you find more resources. Strawberries are a standard for DNA extraction, but you can get DNA from many other fruits and vegetables.

Please post again (in this same thread) if you have more questions.

Heather