Unlocking DNA In Your Own Home…Stir, Don’t Shake


When thinking of solving a convoluted murder case we often picture highly-trained, highly-skilled scientists releasing DNA from a bloody glove or sock. On TV we see experts hovering over steaming vials, boiling test tubes, and genetic analyzers. We read about the protagonist who magically locates key pieces of DNA in the most improbable locations. Sure, the science of DNA is pretty interesting. But did you know you can actually extract DVD in your own home using everyday household items?

Every living thing has its own unique DNA, including plants. In fact, the last time I was in a DNA lab we extracted DNA from a strawberry. For the purpose of this home experiment we’ll use an onion, because the smelly vegetable produces a really nice strand of DNA that’s easily seen with the naked eye.


First of all, you’ll need to collect the ingredients needed to unlock the DNA from the onion—approximately 100ml of finely chopped onion, a pinch of salt, meat tenderizer, rubbing alcohol, dish detergent, and 200ml of ice cold water.

Now place the chopped onion, salt, and ice water into a blender. Blend for approximately fifteen seconds (this separates the onion cells). Repeat the blending for another 20 seconds, or until the mixture becomes foamy, like the beginnings of a meringue.

Pour the foamy mixture into a glass container and add 1/6th of dish washing liquid as there is mixture (yields two tablespoons).

Swirl soap through mixture and then pour into test tubes until each tube is about 1/3 full.

Sprinkle a pinch of meat tenderizer into each tube. The tenderizer acts as an enzyme that cleans proteins away from the DNA.

Tilt the test tubes to one side and slowly pour in rubbing alcohol until the tubes are 2/3 full. The alcohol forms a separate layer at the top of the tubes.

Insert small stick or glass rod into the alcohol layer (the DNA will rise to the alcohol layer) and slowly twist in one direction (either clockwise or counter-clockwise). DO NOT shake the test tubes.


The onion DNA wraps itself around the stick, or rod (the DNA slightly resembles a sperm cell).

Remove the DNA from the tubes.

There you have it, your own DNA lab in the comfort of your own home. No back logs and no cross contamination from other scientists and samples. The question is, “Did the onion do it?”

30 replies
  1. Bob Mueller
    Bob Mueller says:

    This looks really cool. I question one thing though. Twice it says to fill the test-tube to the 2/3 point, in paras 6 & 8. I assume para 6 should say 1/3?

  2. Sewicked
    Sewicked says:

    Forget the kids, _I_ want to do this. But I did share with some parental friends, to share w/ their kids.

  3. Sheila Connolly
    Sheila Connolly says:

    I realized the world had changed when my elementary-school daughter came home one day many years ago with one of those little glass vials. I asked, “What’s that?” “DNA,” she said. Oh my.

  4. Lee Lofland
    Lee Lofland says:

    Rita – Weren’t you one of “those” girls? 🙂

    Rick – I guess you and I have been shoved to the curb to make room for more firemen. Looks like the conference next year will be called The Writers Fire Academy.

  5. R. McMahan
    R. McMahan says:

    Hotness factor? Hot factor…I think that’s also the reason Lee lost his case against convicting Jack Reacher at trial!

  6. Rebekah
    Rebekah says:

    All that pink is just my big, wide smile.

    It’s all for charity, right? Tell them not to forget their sunglasses.

  7. Rebekah
    Rebekah says:

    Maybe next year we can add a “Volunteer Fire Dept. for Writers”. I can only imagine what the Night Owl session for that would be like.

  8. D. Swords
    D. Swords says:

    I wasn’t going to say anything, Lee, but it’s a good thing you three finally complied. I kept hearing this clicking sound and it took me a minute to realize what it was.

    It’s a good thing Crawford’s shotgun was unloaded!

  9. janirvin
    janirvin says:

    Today I went to court as a witness to a shoplifting. The amount the guy stole hiked him up into the felony category. Talk about timing…coming on the heels of the Writers Police Academy, I felt like I was doing post-grad work.:) I had the chance to observe the Municipal Court area as it conducted preliminary hearings on cases. I talked to a woman there for domestic violence and to another whose son had drunk and disorderly and a few other charges against him (she didn’t think he deserved all those citations). I listened to one guy brag about being a petty criminal and how he never does anything that would bump him up to felony. A police officer near me said, “I’ll have to take a good look at that guy ’cause I’ll be seeing him again.” It was a huge learning experience for me. Anyway, I was called in to tell my story. Now the case goes to the grand jury, and I have very authentic material to work in to my stories. Too bad it comes at such a cost to society.

  10. Lee Lofland
    Lee Lofland says:

    meanqueen – The difference in the tours you get during a citizens academy and what we presented (I know because I’ve taught both) is in the detail – we opened the doors to the private stuff the public is not normally allowed to access.

    Yes, the fire department guys were a huge attraction. I think at one point there was talk of waving dollar bills…

  11. queenofmean
    queenofmean says:

    Thanks, Lee, for the advice. In discussing the CPA, I know they make trips to the 911 center, training academy & mobile crime unit, but don’t usually do tours of any other facilities. So, in that aspect, the Writer’s Police Academy would be good. Plus agents & publishers on hand.
    And it sounds like the Hamilton Fire Dept is another incentive!

  12. Lee Lofland
    Lee Lofland says:

    Joyce – I think if we conducted an actual show of hands many of the attendees would have preferred to handcuff the firemen and then take them home. There was much discussion among several conference-goers about a calendar featuring those guys because they were hot (the attendee’s words, not mine), and they didn’t mean from fire. Needless to say, the Hamilton Fire Department was a huge hit.

  13. Lee Lofland
    Lee Lofland says:

    meanqueen 🙂 – I strongly urge you to attend a citizen’s police academy. There’s nothing like actually participating to get the full benefit.

    However, I’d also love to see you attend the Writers Police Academy as well. We’re teaching the inside information and techniques that you won’t get in the standard citizen academies. A citizens police academy experience is entirely different than what conference-goers received in Hamilton last weekend. Apples and oranges.

    And, the Writers Police Academy is designed for writers, where the citizen’s police academies are not. We give you what you need for your books. AND we have agents and publishers on hand ready to hear your manuscript pitches.

    By the way, our event is non-profit. All the proceeds go to the local literacy council. The modest conference fee is well-spent.

  14. Joyce Tremel
    Joyce Tremel says:

    I wish I could have been there!

    I don’t know what I would have liked more though–riding in your car during the pursuit or slapping the cuffs on you.

  15. queenofmean
    queenofmean says:

    Sounds like it was a great conference, Lee. Well, you’ve pushed me out of my procrastinating mode. I’ve decided it’s time I get off my butt & sign up for our local CPA. Thanks for keeping us informed about the conference. I’ll have to put on my list of to-do’s for next year.

  16. Lee Lofland
    Lee Lofland says:

    Bobby – Yep, you missed a great event. One of my favorites.

    You’re right. Those two cops were not playing. That’s what I get for not complying with their orders!

  17. Bobby M
    Bobby M says:

    Sounds like I missed a great learning experience. And as far as your “arrest,” Lee, I did warn you that Barney would NOT be the one slapping on the cuffs. :-]

Comments are closed.