Strawberry DNA Extraction and an Introduction to Genetics: At-Home Science

Strawberry DNA Extraction: Exploring Genetics at Home

Looking back during the ongoing pandemic, it truly is amazing how individuals across various areas of education have come together to support each other. As we endeavor into distance learning, I have seen teachers from across the world coming together to help each other provide enriching instruction remotely.  Memes and funny stories shared on social media echo a new appreciation for teachers, as parents and caretakers assume the role of learning facilitators. I myself have had parents of former students ask for tips and tricks to help them during this time. In an unexpected turn of events, in a time where we’re practicing social distancing, we have become better communicators. 

We may be separated physically, however, we are fortunate to live in a time where we are able to communicate virtually. This provides educators an opportunity to interact with families in new ways. One way to connect with families, and make learning fun for all, is by encouraging families to participate in hands-on learning, such as home labs, together. The strawberry DNA extraction activity is a fun, simple home lab that you can share with your families. Teachers can share the materials needed ahead of time and guide families as they complete the activities, or teachers can share the directions for families to complete on their own time. 

The strawberry DNA extraction will pique the curiosity of students and families alike, regarding DNA, the hereditary material found in humans and nearly all living things, which make up our genes. The activity can be conducted before or after viewing Ken Burns’ The Gene: An Intimate History. As with other Ken Burns content, you can find standards based aligned resources for The Gene: An Intimate History on PBS LearningMedia. The series and resources are a great supplement to your digital learning curriculum. 

The strawberry DNA extraction activity can be completed with many items that are already found in homes. Since the activity does require the use of rubbing alcohol, it is recommended that teachers only suggest this activity to parents, under the premise that students be under adult supervision.

Strawberry DNA Extraction Activity

Materials (per student/participant):

• 1 resealable plastic bag (per student/participant)
• 2 to 3 strawberries (fresh or frozen)
• 2 tbsp dish detergent 
• ½cup water
• 1 pinch salt
• 2 clear plastic cups
• 1 coffee filter
• ⅓ cup cold rubbing alcohol (pop into the refrigerator at least 1-2 hours before activity)
• 1 wooden stirrer 

Procedures:

1. Gather all materials.
2. Pull off any green leaves/stems that may still be attached to your strawberries. 
3. Place the strawberries in the resealable plastic bag. Seal the bag and lightly mash the strawberries inside until you have a pulp. (This process helps break down the strawberries’ cells)
4. In 1 plastic cup, mix the detergent, salt and water. Add a few tablespoons of the mixture into the plastic bag. Reseal. 
5. Lightly smash the strawberries again, to mix with the solution.  
6. Grab the second plastic cup and the coffee filter. 
7. While keeping the filter in place, pour the strawberry mixture into the plastic cup. 
   1. You may use one end of the stirrer to help the solution filter through. 
8. Remove the coffee filter and add in the cold rubbing alcohol. 
9. After a few seconds, you will see the strawberry mixture separate, leaving a white, cloudy film on top. That’s the strawberry’s DNA! (Adding the alcohol causes the DNA to bind together and float.) 
10. Using a clean stirrer, gently pick up the DNA from the mixture, to allow you a closer observation. (Reminder: the mixture now has rubbing alcohol and detergent which are not safe for consumption.) 

Strawberry DNA Extraction Experiment: Resources for Further Learning

• The Gene Official Website
• The Gene Animated Series: Everybody is talking about genes. Your body is filled with them. You look the way you do because of them. But do you really know what a gene is? This animated series won’t get you a PhD, but it does clear up a few mysteries about how genes work, how they make us, if we can change them and what they might look like in the future. (Microscope not required.)
• PBSLM The Gene: An Intimate History Collection
  • Genetics, History, and the American Eugenics Movement:To take advantage of the promise of genetics, how can we as a society avoid the mistakes of the past? This lesson delves into the dark past of genetics—eugenics—using clips from the film The Gene: An Intimate History and a guide to leading student discussions about this challenging topic.
  • Using Primary Sources to Examine the History of Eugenics: This lesson uses primary source documents to explore issues of race, gender and class in the 20th century. The goal of this lesson is for students to use original sources to understand how the eugenics movement used propaganda to enter mainstream America to promote its agenda, and use critical thinking skills to analyze and interpret the sources.
  • Genome Editing and CRISPR: How might advances in our ability to change genomes impact individuals and society?
  • How Protein Synthesis Helps Pick Your Nose: Students will explore how a cell uses information from genes in DNA to produce the proteins that help determine the traits of an organism.
• KQED Learn Discussion: In this KQED Learn Discussion based on The Gene: An Intimate History from Ken Burns and Barack Goodman, students will have the opportunity to learn about and discuss eugenics, a pseudo-science that claims people can improve humanity as a whole by regulating who is allowed to reproduce and who is not. KQED Learn is a discussion and media creation platform for students in grades 6-12. Each discussion comes with a writing prompt, media-creation activity and educator guide.

Republished with permission from PBS Learning Media.