Teeth scrapings. Tribute to Anton van Leeuwenhoek 


On September 17th 1683, van Leeuwenhoek wrote to the Royal Society describing moving ‘animals’ (bacteria) in the plaque between his teeth.

It struck me that today was sept 17th as well and as a tribute, I roped Matt (only person around) to help me find a toothpick and got to work.

If you watch the video above, you’ll realize that we don’t see any bacteria. I still decided to upload it, to encourage others to check their teeth and see if they have more success.

Interestingly, Leeuwenhoek himself didn’t see any moving bacteria till he mixed rain water/spittle with the white plaque.


If you read the whole article, you’ll notice that he finds bacteria in the teeth of 8 year olds. So if you are an 8 year old reading this, please upload your findings with teeth scrapings.

Upload even if not 8 year old.


Manu collected some teeth scraping and sent me these beautiful videos.

I’ve added a screenshot to indicate where to focus your eye on in the accompanying video.




5 Comments Add yours

  1. Manu says:

    @SB: at the moment I read your post; I repeated the experiment. Here is the result.. You have to watch the same carefully to actually see spirochetes swimming. They are incredible – tiny lines of spiral (sprig like objects) crawling around in my own mouth. Don’t wory – you have got them too 🙂

    If you want, you can embed them in this post.


  2. Saad Bhamla says:

    @Manu – included.
    I also added a screenshot. Feel free to add a few sentences 🙂


  3. laksiyer says:

    This is great, I have seen large spirochaetes in pond water too and the corkscrew motion is just fantastic to see. One method that we used to use as undergrads is the hanging drop method. A drop of culture is placed on a coverslip and put on a cavity slide such that the drop is hanging. (We used to seal the coverslip with vaseline). I dont know why but it would give great motility views. In combination with dark field it used to be great with compound microscopes. I didnt try the hanging drop thinking that the distance from object to lens has to be small in a foldscope, but I should try it.

  4. Manu says:

    @laks: I am excited to hear about this hanging drop method. I don’t know why it should matter; but worth trying. I noticed several organisms spinning in place; but not moving that much (possibly due to being close to the surface).

    Do you think the curvature has anything to do with it. Can you sketch what you mean; I wish we had a little sketching method next to writing text messages. Will look for a plugin now 🙂


  5. laksiyer says:

    Dear Manu. The standard explanation was that aerobic bacteria are attracted to the interface and hence they crowd at the edge of the drop. But I used to find that a bit hard to understand as I didnt know that an O2 gradient in the drop would be that significant. Perhaps you might be able to compute this. I will be conducting a few hanging drop experiments this weekend and will post the pics.

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