One of my favorite science experiments is the DNA extraction lab where kids learn how to extract DNA from strawberries or another fruit. NGSS has it as a high school activity, but I routinely do it as part of middle school STEM activities and even with elementary kids.
I think it’s really fun for kids of all ages and really dives into the lab work part of science in a safe way.
Keep reading to learn how extracting DNA from fruit works!
What is a DNA Extraction Lab?
In this experiment, you are extracting DNA from fruit! It’s a multi-step science experiment that you can use to explore what DNA strands look like up close!
Strawberries are often used because they have a lot of DNA that is easily extractible. You might not get as much DNA using another fruit, but any fruit will work!
DNA Lab NGSS Alignment
Technically, the NGSS alignment for this activity is high school. But I use it in middle school and elementary all the time.
It’s OK to go rouge sometimes!
HS-LS3-1. Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring.
Although the NGSS alignment for this lesson is high school, I find that kids of all ages love doing DNA extraction.
How to Extract DNA from Cells
Follow along with this video and the experiment below to learn how to extract DNA from fruit.
DNA Lab Science
The science behind the DNA extraction experiment is simple. DNA is coded into every cell in any living organism so it can replicate.
Normally, DNA strands are tightly woven inside of a cell, but with a combo of soap and salt, the cell walls are broken down and the DNA strands are released.
The alcohol then lifts the DNA strands from the rest of the cells isolating them so the DNA can be examined.
DNA Extraction Lab Hypothesis
There are a few hypotheses you can apply to this science lab.
- Is it possible to isolate DNA from cells?
- Is there a difference in how much DNA is extracted depending on soap type?
- Does the DNA of all fruits look the same?
- Which type of fruit produces the largest amount of DNA strands?
Any of these questions are a great place to start!
DNA Extraction Lab Supplies
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DNA Extraction Lab Lesson Plan
Grab the lesson plan for this experiment below!
How to Extract DNA from a Strawberry or Another Fruit
Here is how to extract DNA from a strawberry! Kids will have a lot of fun with this hands-on science lesson.
Before getting started, put a 1/4 cup of rubbing alcohol into the freezer.
First cut up your fruit into tiny pieces.
Next, line a jar or cup with a plastic baggie and add the berries.
Add a tablespoon of dish soap and a teaspoon of salt. Add 1/3 of a cup of water.
Seal up your bag and squish all the ingredients together until it makes a pulp.
Place a coffee filter over the top of your jar to make a filter. You may find it helpful to hold it in place with a rubber band.
Pour the goo over the filter into the jar to isolate the juice.
Pour the juice into your test tube.
Cover the juice with a 1-inch layer of rubbing alcohol.
Watch as a snotty substance rises to the top of the rubbing alcohol. This is the DNA!
Use an eyedropper to isolate the DNA strands and examine it with a microscope.