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10 years and up Classroom Activity Creative Commons


Using household chemicals you can isolate DNA from bananas in just a few steps.

Chemicals for DNA Isolation

  • Buffer: 53g Salt (NaCl) in 1 liter of water
  • Detergent: 10% washing-up liquid in water (100ml in 1 liter)
  • Alcohol: 95% ethanol
  • Water


Beakers, forks, Erlenmeyer-flasks, matching funnels, pipettes, pipetting controllers, falcon tubes, Pasteur pipettes, Eppendorf tubes, paper towels, cleaning cloth


1. Mash 2-3 cm of banana with a fork.

2. In a beaker mix 12 ml of Extraction buffer and 3 ml of detergent.

3. Add the banana mash and mix well.

4. Filter the mixture into an Erlenmeyer-flask using a funnel lined with paper towel. Make sure to wet the paper towel before filtering.

5. Transfer 1 ml of the filtered solution to a falcon tube.

6. Mix with 1ml water.

7. Carefully cover with a layer of cold alcohol (8ml).

8. The white material appearing between the phases is the banana DNA.

9. Dip the Pasteur pipette in the tube, slowly rotating it to spool out the banana’s DNA, transfer the DNA to an Eppendorf tube.

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