How to Extract Your DNA

Three Parts:Extracting DNAIsolating Your DNAHaving Your DNA Sequenced or Analyzed

Deoxyribonucleic acid (DNA) is stored in every one of your cells and contains your body's genetic material.[1] Most bodily fluids contain DNA, including saliva, blood, semen, urine, and feces.[2] There are numerous ways to extract DNA, but many involve visiting a lab to submit a sample of blood or other bodily fluids. If you want to extract your DNA at home, saliva is the easiest, most non-invasive, and most sanitary DNA source to sample.

Part 1
Extracting DNA

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    Create a mouth rinse. To extract your DNA from saliva, you'll need to create a mouth rinse first. You'll be mixing salt into water, because salt provides a rough, granular texture to help collect cells from your mouth. It also helps protect the negative phosphate ends of your DNA, allowing it to precipitate out of the saliva.[3]
    • Mix one tablespoon of salt into 500 milliliters of clean drinking water. Stir until the salt is dissolved, then measure out three tablespoons of the rinse into a clean, clear cup.[4]
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    Gargle with the rinse. Using the smaller cup with three tablespoons of saltwater, pour the rinse into your mouth without swallowing. Gargle and swish the rinse around in your mouth for at least one minute.[5]
    • While swishing the rinse in your mouth, gently scrape your teeth against the insides of your cheeks. This will help release additional cells to be suspended in the saltwater.[6]
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    Spit back into the cup. After about one minute of gargling, swishing, and gentle scraping inside your mouth, spit the rinse back into the smaller, clear cup. You will not be able to see it with the naked eye yet, but cells from your cheeks are now suspended in the saltwater rinse.[7]

Part 2
Isolating Your DNA

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    Add dish soap. Carefully squeeze out one drop of dish soap into the cup containing your used saltwater rinse.[8] Gently stir the soap into the water without making creating bubbles. Alternately, you can make a diluted solution of two parts water to one part soap, and gently mix one teaspoon of the diluted solution to the used saltwater rinse.[9]
    • Soap breaks down the cell's membranes and nucleus, releasing your DNA directly into the saltwater.
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    Pour in rubbing alcohol. Measure out 100 milliliters of rubbing alcohol (isopropyl). Carefully add this to the saltwater by tipping the DNA cup at an angle (approximately 45 degrees) and pouring the alcohol against the side of the cup.[10]
    • The goal is to pour the alcohol gently enough that it forms an undisturbed layer on top of the saltwater.
    • Alcohol helps precipitate your DNA while leaving the other components of the cup in the original solution.[11]
    • Do not drink any of the isopropyl alcohol. This type of alcohol is extremely dangerous and is not meant for human consumption.
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    Wait for the DNA to separate. After approximately two to three minutes, you should begin to see clumps and strings of a white substance form between the saltwater and alcohol layers (though it may take up to 10 minutes for these clumps to fully form). Those strings and clumps are your DNA precipitating out of the saliva and saltwater.[12]

Part 3
Having Your DNA Sequenced or Analyzed

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    Purchase a DNA kit. There are numerous types of DNA kits commercially available. These kits are designed to collect your saliva or a cheek swab and preserve the sample. Please note that these kits allow you to collect your DNA at home, but require you to mail your sample to a lab or testing facility in order for your DNA to be sequenced.
    • The most common methods of saliva DNA collection are whole-saliva collection (spitting directly into a container), buccal swab/brush collection (using a swab or specially-designed brush to gently scrape the insides of your cheeks), and oral rinse collection (described above).
    • Of the three methods of collection, whole-saliva collection provides a significantly higher yield of DNA.[13]
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    Collect your DNA. How you collect your DNA will vary, depending on the type of kit you've purchased. If using a brush or swab, you'll rub the collection device against the insides of your cheeks for approximately 30 seconds to a minute. Some kits may require you to use a stabilizing rinse immediately after scrubbing your cheeks. Do not swallow the rinse. You will need to spit it out into a bottle, if using a rinse.[14] If using a whole-saliva collection method, simply spit into the tube or container that came with your kit until your liquid saliva (excluding bubbles) reaches the marked fill line.[15]
    • Some kits require you to vigorously shake your sample. Others do not. Follow the instructions on the kit that you've purchased.
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    Deliver the sample to a lab. Some kits will include an address that you can mail your completed sample to. Others will not, and you may need to find a lab near you that will sequence/analyze DNA. You can find labs in your area (if you need to) by looking in a phone book or searching online and looking at the services offered by local testing laboratories. If the kit you purchased includes mailing instructions, follow those packing and shipping instructions to send your sample off for sequencing.
    • DNA sequencing can tell you vital information about your genetics, your lineage, and even your risk of certain genetic diseases. DNA sequencing can also help pregnant couples determine the risk that their child will carry a genetic mutation or disease.[16]


  • This process works best if the alcohol is chilled, though it is not strictly required. For best results, you may want to keep the alcohol in the freezer for an hour or so before you try this experiment.


  • Be sure to wash out the containers used in this experiment before you use them again for food and drink, as some of the ingredients are poisonous.

Things You'll Need

  • A measuring device that uses ml (such as an eye dropper)
  • A small, clean cup with water in it
  • 3 clean glass containers you never plan on using for food or drinks
  • Some rubbing alcohol (the more pure, the better)
  • Liquid detergent
  • Salt
  • Distilled water

Article Info

Categories: Biology