An Unusual Use of Alcohol to Extract DNA From Cells

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Intro: An Unusual Use of Alcohol to Extract DNA From Cells

Today, I am going to show you guys how to extract your DNA (Deoxyribonucleic Acid) very easily with a little amount of supplies! First, let's gather our home supplies to do this easy project. Don't forget to vote for me in the Explore Science and Unusual Uses contest!

You will need:

  1. Required - Distilled water - This is used to hold your cells so that they can be broken down.
  2. Required - 1 Paper Cup - Any cup will do but you will have to spit in it.
  3. Required - Toothpick - This is to scrape off the loose cell inside your mouth.
  4. Required - Frozen Ethanol - You cant freeze ethanol but it can get very very cold at sub zero temperatures. The ethanol is the hardest part of this project because it is not a very common house item (Unless you are a scientist). This means that you will have to buy it online or you can ask your local pharmacy if you can buy some. If you have the time and patience, you can make your own ethanol through a process called alcohol fermentation. If you feel adventurous, here is a detailed video on how to make it. NOTE: I have not tried this project with homemade ethanol so I am not sure If you will get above 95% ethanol from your fermentation which you need to make this project work.
  5. Required - Small transparent tube- I used a disposable microcentrifuge tube which can hold up to 2mL of your DNA.
  6. Small ribbon - This is to hold the tube like a necklace or to have it hanging.
  7. Pipette - This makes life easier when you want to transfer the DNA and the liquid around it into the tube. You don't need this, you can just pour it instead with you very steady hands.
  8. Test Tube - You can use one of the paper cups to replace this but then you wont see the "Magic"

STEP 1: Getting the Cells Into the Distilled Water

First what we have to do it take a toothpick and start to scrape off the cells inside our mouth by applying some pressure the the inner side of your mouth. Do this for about a minute but make sure to NOT SWALLOW THE CELLS or else the experiment is now in your stomach. Once you have scraped for a minute, you will want to fill one of the paper cups with about 3/4 of a centimeter high with distilled water and then swish the water around for another 45-60 seconds. Oh and the water may taste a little strange but try to keep it in. After that is done, spit out the water, which now has your cells, and place it back into a paper cup or a beaker like shown.

STEP 2: Pouring the Contents Into the Test Tube

Once you have put the distilled water and the cells into the cup, you can then swirl it around and the put it inside the test tube for what we will do next. However, if you do not have a test tube or something that is clear and tall, you can either leave it in the cup or put it in something that can hold a reasonable amount of liquid.

STEP 3: Pouring the Very Cold Ethanol

This step is the most important step of all. Pouring the ethanol can be easy but you need to keep it in the freezer until the last second you use it so that it works best. You want to put the same amount of ethanol in the test tube as there was cells and distilled water. For me that was about 2 cm in height on the test tube I was using.

STEP 4: Watch As Your Test Tube Starts to Break Down Your Cells Leaving the DNA


Once you put the ethanol in, you should start seeing some bubbles and little strands of sting like material growing. That is your DNA! The longer you wait, the more DNA you can collect until there are no more cells for the ethanol to break down.

STEP 5: Taking the DNA Without Breaking It.

After you have your DNA and the mixture of distilled water and ethanol in the test tube and you decided that there will not be a significant amount of DNA that will grow anymore, you can remove the DNA from the tube. You can do this by using a pipette and taking the cloudy white substance along with some of the water and ethanol so that it keeps its form in the container.

STEP 6: Putting the DNA Into a Container With Delicacy

Once you have the DNA and some of the ethanol/water, you can tilt the container a bit and put the tip of the pipette to the wall. Then when you release the mixture, the liquid will run down the side and bring the DNA down in the container. Then if you want, you can make it look nice.

STEP 7: Cleaning and Making Your Product Look Nice

Do you want to make your DNA look nice and hang it from something to remind yourself that a part of you is in that container? Well, what I did was put on a piece of ribbon on the clip on the tube and closed it so that it would hold. Then I tied knot at the end of it so that I could hang it on the wall as a decoration.

STEP 8: Final Thoughts

In conclusion, I think this was very fun and easy project. Anybody with about 30 minutes of time can do this and not have to be a professional scientist. If you have any questions about this project or any other ones I made, you can email me at legocad@gmail.com or leave a comment below and I should respond quickly :D. Thanks!

15 Comments

And exactly what do you do with your DNA after this? Is it pure enough to use for testing to yield your DNA profile?

I would Imagine you could use it to test unless the Ethanol makes any changes to the gel!

alcohol denatures the DNA. It is not helpful for anything practical after the alcohol bath..

To determine your DNA profi there are a few ways it is done. The old way that most people are familiar with is using a series of enzymes to cut up your dna into segments then putting it on a gel and running an electric charge through it for a given time period and comparing the bands that form to another specimen to look for a match.

The next method,developed in the 90's is shotgun sequencing.. You chop the dna up into a bunch of pieces then put special labels on the dna (i.e. Color) and run those fragments through a machine then look for common pieces and overlaps to get the sequence.

Next comes the newest generation. High throughput sequencing. Basically like shotgun but with a bunch of machines.

BUTTTT. DNA has to be pure and unaltered to do the above...If I remember correct.

Thank you so much for teaching me this! I am not a professional and rather a 15 year old doing projects wherever i can!

check out DNA crystallization for some cool looking atuff

and

https://en.wikipedia.org/wiki/Ethanol_precipitation

Interesting. Nice way to use or see it better so that you can look under a microscope or just for looks!

Just FYI: 95% Ethanol IS a common household item in most of the world, as part of the basic medkit. It's just in countries where "rubbing alcohol" (70% isopropyl) is used instead that ethanol is harder to find.

many places will sell 95% drinking alcohol which is ethanol and will do just fine.

Yep. Usually those places are mutually exclusive with the places where medical alcohol is 95% ethanol. Yet, that means in BOTH places 95% ethanol is readily available - be it for external or internal usage. ;-)

There surely will be some DNA in this mixture, but there will be much more other stuff, even what is broken by ethanol still is there, in a changed form. Any idea how to filter it?

Without breaking the DNA, I am not sure how to filter the other things out. Sun dry XD?

A much more useful way to collect the DNA.... Do the steps as above up to and including adding the alcohol. Next, take anything round, tooth pick for example, or glass stir rod or even a plastic one and twirl it in the mixture of alcohol, cells and water. The DNA strands will form around your rod. Then you can use water to remove the stranded DNA and put on a surface to dry or you can let it dry on the rod and gently remove it. Then you have a dry bunch of DNA.

If you want to harvest MASSIVE amounts then just get some blood from your local butcher or from a nice cut of meat. Then store it in a small glass tube.