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Hello Whyville! This is actingup9 with an interesting science article that I want to share with you. All you'll need are some simple household materials, and
you can extract DNA from wheat germ!
Here are the required supplies:
1 tablespoon wheat germ
hot water
test tube
soap
99% rubbing alcohol
Follow these simple steps, and you'll have extracted DNA from wheat germ:
1. Fill testing tube up with wheat germ.
2. Slowly, add hot water and soap to fill up about half of the testing tube.
3. For five minutes carefully poke and stir the mixture. Make sure no
bubbles appear.
?????? The hot water and soap tear apart the wheat germ molecules.
4. Pour the rubbing alcohol slowly into the testing tube so two layers of
liquid appear.
5. You will notice a white gooze in between the two layers: that's your DNA!
Optional:
Fill another testing tube up with alcohol. Bend open a paper clip and try to dig
the DNA out with it (yes, it does look quite gross) and place the DNA in the
tube to further investigate it.
I found this experiment very neat and it lead me to a lot of additional research
on DNA. The subject is quite confusing, yet very interesting, so I advise you do
some investigations on your own!
Note from City Worker Calliope: What this experiment is attempting to show is what a lot of
scientists call DNA precipitation.?? It's called 'precipitation' because that "white gooze" is called the precipitate or precipitant.?? The??idea behind this experiment is that the soap interacts with the linings inside
the wheat germ cell and break it up so that all the contents inside the cell spill out.?? Then,
the alcohol "salts out" the DNA material so that it's separate from
everything else that gushed out from the cells.
When scientists "prep" DNA, they use a
procedure much like this one, but obviously
with much more fine-tuning.?? They use centrifuges, lysing solutions, chemicals and many
other agents. Can you think of why it might be important to know how to get DNA
from cells?
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