Extracting DNA from fruit

Extracting DNA from fruitSpec 3.6

DNA can be extracted from the cells of fruit such as strawberries or kiwi fruit using simple equipment. Each step has a purpose.

1. Mash the fruit in a beaker. This breaks the fruit into small pieces and separates the cells.
2. Add a mixture of detergent and salt, and stir. The detergent breaks down the cell membranes (and the nuclear membranes) so the DNA is released. The salt helps the DNA to clump together.
3. Filter the mixture. This removes the solid pieces of cell, and the filtrate contains the DNA.
4. Carefully add ice-cold ethanol so that it forms a layer on top of the filtrate.
5. Look at the boundary between the layers. DNA is not soluble in cold ethanol, so it comes out of solution as white, stringy strands. These can be lifted out with a glass rod.