April 24, 2020

How to extract DNA from strawberries

Postdoctoral associate Sarah Dewell shares a fun activity to try at home for National DNA Day

April 25 marks National DNA Day which honours two landmark achievements in genetics; the discovery of the double helix structure of DNA and the completion of the human genome project!

Both of these accomplishments pushed forward the study of genetics and have brought us to the era of genomic medicine and precision health.

During the race to complete the human genome project, there was a lot of focus on developing more efficient and accurate methods to sequence DNA. Improvements continued after the human genome project ended resulting in current technology that enabled rapid sequencing of the COVID-19 viral genome.

I wanted to share these activities and links to spark discussion of the important role nurses play in implementing genomic health care and the need to increase our capacity to lead and shape changes to practice.

Fun fact: Strawberries have lot of DNA in their cells; it is because they are octoploid, meaning they have eight copies of each chromosome. Human cells are diploid, meaning two sets of chromosomes.

Extracting DNA from strawberries is a fun, easy activity that can be done by anyone with a just a few household ingredients. I had hoped to do this activity in-person with students, staff, and faculty, but as we can’t be together right now, I thought the video was the next best option.

Hope everyone has a great DNA Day!

Strawberry DNA extraction video

This video includes everything you need to know about getting DNA out of strawberries.

 

What you need

  • 1 re-sealable plastic bag
  • 2 strawberries (fresh or frozen)
  • 2 tsp dish detergent
  • 1/2 cup of water
  • 2 plastic cups
  • 1 coffee filter
  • 1/2 cup COLD rubbing alcohol
  • 1 coffee stirrer

 

What to do

Step 1: Put strawberries in a sealable plastic bag and seal, making sure to get most of the air out.

Step 2: Mash strawberries to start to break open cells.

Step 3: Make lysis solution containing 1 tsp. salt, 2 tsp. dish soap (or other soap), and ½ cup of water, stir all ingredients together

Step 4: Add lysis solution to bag of strawberry mush and mix gently to avoid making too many bubbles.

Step 5: Filter strawberry solution through a filter (coffee filter, paper towel, etc.) into a clean plastic cup. Squeeze filter gently to get all the liquid into the cup.

Step 6: To precipitate the DNA, add about the same amount of cold isopropyl alcohol (also called rubbing alcohol) as there is strawberry liquid. Do not mix or stir.

Step 7: The DNA will appear at the top of the solution and you can then pick it up with a popsicle stick, stir stick, etc.

 

For a printable PDF of the steps, click here.

To make your own Origami DNA, print off this template and follow these instructions.

This activity and more can be found at genome.gov/dna-day

 

For more information about genomics and nursing, check out the following sites: