Dna extraction

• Why are strawberries suitable for DNA extraction?

  They can have up to eight copies of each chromosome
• What visible form does the extracted DNA take?

  White threads
• What is the method for extracting DNA from strawberries?

  1. Crush the strawberry in a sealed plastic bag for 2 minutes.
  2. Mix 10 cm³ of washing up liquid, 1 g of salt, and 100 cm³ of water in a beaker.
  3. Add 10 cm³ of the extraction liquid to the strawberry and mix for 1 minute.
  4. Filter the mixture.
  5. Pour 10 cm³ of ice-cold 90% ethanol into the mixture without stirring.
  6. Observe the formation of a white cloudy substance and pull out the DNA with a lolly stick.
• What is the role of washing up liquid in the DNA extraction process?

  It breaks down cell membranes and releases the DNA
• How long should the strawberry be crushed in the plastic bag?

  About 2 minutes
• What is the volume of the extraction liquid added to the strawberry mixture?

  10 cm³
• What should you do after adding the ethanol to the strawberry mixture?

  Do not mix or stir
• What happens to the DNA when ethanol is added to the strawberry mixture?

  The DNA separates out into a layer
• What tool is used to pull strands of DNA from the top layer?

  A lolly stick
• What should you observe after adding ethanol to the mixture?

  A white cloudy substance forming in the clear layer