DNA is the building block of all living creatures, plants and animals. It is found in the cells of animals and determines the genetics or make up of every individual organism. DNA is also present in the whole foods we eat.

Thanks to the special characteristics of strawberries, it is possible to extract, isolate and observe the DNA. You don’t have to be a geneticist. You don’t even need a microscope. All that is needed are some household materials.

The long thick fibers pulled out of the extraction solution are strands of strawberry DNA. DNA is present in every cell of all plants and animals and determines the genetics of the individual organisms.

 While other fruits are soft and just as easy to pulverize, strawberries are the perfect choice for a DNA extraction lab for two reasons: they yield more DNA than any other fruits, and they are octoploid, meaning that they have eight copies of each type of DNA chromosome. These special circumstances make strawberry DNA easy to extract and see. (Human cells are generally diploid, with only two sets of chromosomes.)

To extract the DNA, each component of the extraction solution plays a part. The soap helps to dissolve the cell membranes. The salt is added to break up protein chains that hold nucleic acids together, releasing the DNA strands. Finally, DNA is not soluble in isopropyl alcohol, and even less so when the alcohol is ice cold.
For step by step instructions and photos, please visit the Strawberry DNA experiment on SteveSpanglerScience.com
3 replies
  1. Alejandro Torres
    Alejandro Torres says:

    Steve how do I make this into a science fair project what do I compare it to I cant just extract dna I need something to do with it or something please respond I have 20 days!

    Reply
  2. Susan Wells
    Susan Wells says:

    Hi Alejandro – a great science fair project contains variables and tests each one to see which one works the best or doesn’t and then compares the results. To turn this into a science fair project, try changing or switching out one of the materials with something else. Instead of using salt, test baking powder or sugar. Or substitute the dish soap with other materials. Think about it in terms of testing different substances to see if you get the same result.

    Reply

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *