How can you extract DNA from a kiwi?

Answer

Dear Ella,

Getting DNA from a kiwi is relatively easy and you can even do it at home. The information you provide comes from the following website: http://www.uk.rug.nl/archief/jaargang37/16/08b.php

People from secondary school often visit our lab, who we also have it performed, and it almost always works, even with vodka instead of highly concentrated ethanol. If you want to use methylene blue (as stated at the very bottom): be VERY careful, because this will stain everything, best do it outside with material that can possibly go away!

Start of the recipe:

To start, make a solution of 120 ml of water with 1.5 grams (1/4 teaspoon) of table salt and five grams (1 teaspoon) of baking soda. If you want to get it right, use demineralized or distilled water from the supermarket. Then make a second solution of 100 ml of water with 5 ml of liquid detergent or shampoo.
Now put the flesh of half a kiwi or banana in a bowl or glass, add 20 ml of the baking powder solution and mash the whole with a fork or with a stick blender. Now add 30 ml of the second solution and gently swirl the mixture back and forth for a few minutes so that everything mixes well. Then wait about five minutes.
Now put a coffee filter in the funnel, place it in a tall glass and pour the kiwi juice through the filter. The filtrate (the ‘coffee’) contains the dissolved DNA. When all the sludge has run through the filter – that can take a while, by the way – very carefully pour an equal amount (i.e. 20 ml by 20 ml) of ice-cold alcohol into the solution. Preferably use alcohol (ethanol) with the highest possible concentration (around 70 percent, available at the better drugstore). You can also use vodka or single malt from the freezer, although that somehow doesn’t seem like a good idea. Let the alcohol run very slowly along the wall of the glass via a spoon. The trick is that DNA does dissolve in water but not in ethanol; the DNA clumps together in the form of white, semi-transparent streaks at the interface between water and alcohol. You can remove those strands from the solution by gently stirring them with the tip of a skewer.
You can isolate your own DNA by rinsing your mouth extensively with the baking soda solution. Spit it into a glass and proceed as described above. The DNA will be more visible if you stain the solution with one or two drops of methylene blue from the aquarium store.