Ever wondered how are DNA extracted?
Well, here’s your chance to try DIY DNA extraction, in the comforts of your own home!
We’ll guide you through step by step, and before you know it, you’ll extract, isolate and observe the DNA of strawberries.
What you’ll need
- A clean clear glass
- 2 strawberries.
- Dishwashing liquid
- Table salt
- Resealable plastic sandwich bag
- Rubbing alcohol (99% isopropyl alcohol)
- Coffee filter
Step 1: Smash the strawberries
Remove any green top from the strawberries. Put the strawberries into the resealable plastic sandwich bag and seal it tightly.
Use your fingers to squeeze and smash the strawberries for 2 minutes until they become a pulp.
Step 2: Break down the strawberry cells.
In order to extract the DNA, we have to break down the strawberry cell membrane.
Prepare your extraction solution by combining 1/2 cup of water, 2 teaspoons of dishwashing liquid and 1 teaspoon of table salt. Make sure you stir the solution until all the salt has dissolved.
Add 3 tablespoons of the extraction solution into the resealable plastic bag containing smashed strawberries. Re-seal the bag tightly and gently squeeze the mixture in the bag with your fingers for 1 minute.
When you add the extraction solution to the smashed strawberries, the dishwashing liquid helps break down the strawberry cells so that the DNA can be released. The salt creates an environment where different DNA strands can clump together, so that it’s easier for our eyes to see the DNA strands.
Step 3: Filter to separate the pulp.
Now that you have released the DNA from the strawberry cells, it’s time to filter our the big chunks of strawberry pulp.
Place the coffee filter over a clean clear glass. Make sure you hold the filter in place, and gently pour the contents in the sealable plastic bag onto the filter.
You can twist the filter and gently squeeze the remaining liquid into the glass. If you see any strawberry solids in the glass, repeat the filtering step with fresh new filter papers.
Step 4: Check out these strawberry DNA.
All the strawberry DNA are in the filtered liquid inside the clear glass, and you should be able to see the red liquid.
Tilt the clear glass and very slowly pour the rubbing alcohol into the red liquid. Pour until the alcohol has formed approximately a one-inch-deep layer on top of the red liquid. Make sure you don’t mix or stir the liquids.
DNA is hydrophilic so it remains soluble in the liquid. DNA is not soluble in alcohol, so the addition of rubbing alcohol will make the strawberry DNA precipitate (become solid), which makes it visible to the eyes!
At this point, you should be able to see clear/white strings between the alcohol layer and the strawberry liquid. That’s the strawberry DNA and you’ve successfully extracted DNA by yourself!
If you’d like to examine it closer, you can use a chopstick or skewer stick to lift the white stringy DNA gently out of the liquid.
In just 4 simple steps, you have learned how to extract DNA from strawberries.
Was that fun? If you’ve not tried it out yet, make sure you get a friend and do this DIY DNA extraction together!