Extracting DNA from an onion is an easy experiment to do, especially for the mad scientist on a budget. Why an onion? Onion tissue is very watery, and therefore disrupting cellular membranes is quite easy. In order to extract DNA, which is in the nucleus, you have to break the cell wall, the cell membrane and the nuclear membrane. The high water content makes it easier to do this. Onions don't have chloroplasts or starch, being a root vegetable. Onions also have a surprising amount of DNA contained within each cell. Onions are polyploid, where as humans are diploid. Combine these factors and you have some ready to extract Deoxyribonucleic Acid. Then it is just a matter of time before your hideous Onion soldiers have the UN at its knees!

Now, on to the experiment!

5 cm3 liquid detergent
1.5 g of table salt
50 cm3 water
One small onion
A Beaker
A Funnel
A Pan of hot water
A Pan of ice cold water
A Blender
A Paper Coffee Filter
1 drop of Protease Enzyme (scientific supply catalogue time!)
10 cm3 of Isopropanol
A small transparent container with a lid
A sharp knife

Step 1:
Add the table salt to the liquid detergent. Add the water to the salt-soap solution. Stir well until all the salt is dissolved. This all goes in the beaker.

Step 2:
Peel the onion and remove the top and bottom portions. Throw them out. Chop the onion into small pieces and add them to the salt-soap solution. This solution is breaking down the cell membranes and releasing DNA from the nucleus inside each cell. The soap is attracting all the lipids, and in turn disrupting the cellular membranes. The salt is preventing the DNA from attaching to freed sugars and proteins.

Step 3:
Place the onion solution beaker in the pan of hot water (at least 50C, no more than 60C) for 15 minutes. The heat from the water speeds up the reactions that are breaking up the cells. The cells in the solution are in self-destruct mode. Natural enzymes which were released when the onion was chopped are now reactive, and are attacking the cells contents. The heat in the water bath helps promote the endothermic reactions.

Step 4:
After the fifteen minutes, cool the beaker off with the pan of ice water. Be careful switching the beaker. Extreme temperature changes can break glass. If the beaker is left in the hot water for too long the DNA will dissolve, so the cooling bath is important. The enzymes are rendered non-reactive by the decrease in temperature.

Step 5:
Pour the solution into the blender and blend for no more than 5 seconds. The blender helps to break open the onion cells, but more than 5 seconds will damage the DNA. Clean the beaker.

Step 6:
Using the funnel and the filter paper, filter the onion solution back into the cleaned beaker. This separates the cell wall material from the DNA and proteins, which are now in the beaker.

Step 7:
Take the small container and add about 10 cm3 of the onion extract. Then add 1 drop of Protease Enzyme. Seal the bottle and shake one or twice to mix. Protease is a chemical that breaks down proteins. Only a small amount is needed.

Step 8:
Very carefully pour 10 cm3 of isopropanol onto the surface of the onion extract.

Step 9:
Watch carefully. The DNA, which doesn't dissolve in the alcohol, rises to the upper layer. Everything else precipitates down. It looks like thin white fibres of cotton. This is the DNA with some sugars and proteins attached.

Optional 10th Step:
Use the DNA to create your atomic supermen and terrorise the free world.