• Question: Have you ever had to dissect poo?

    Asked by anon-285367 to Felicity on 3 Mar 2021.
    • Photo: Felicity Hunter

      Felicity Hunter answered on 3 Mar 2021:

      Hi Leo. Thanks for the excellent question! I like your use of the word ‘dissect’. The answer is yes! I have dissected nearly 100 poo samples. I test the number of different types of bacteria living in the guts of animals by measuring the bacteria DNA in their poo! I will explain how I do this step by step: Firstly, I collect poo from animals and mash it up into tiny pieces using a tool (and wearing gloves!). I then add some water and chemicals to turn the poo sample into a liquid. Next, I put this liquid poo sample through a filter to get rid of all the unwanted stuff and to draw out the bacteria DNA from the liquid. The filter kind of acts like a magnet because the bacteria DNA from the poo sticks to the filter and all the unwanted material is flushed away through the filter. Next I add a different chemical to the filter to get the stuck bacteria DNA off the filter and into a clean tube. Now I have gotten rid of all the unwanted poo material and I am left with a tube containing only bacteria DNA (dissolved in a liquid). However, the bacteria DNA is in very tiny amounts so it is really hard to measure. To solve this, I use a fancy machine which makes thousands of copies of this bacteria DNA so it is much easier to measure. This machine also tells me how much bacteria was in the animal poo and which types of bacteria species were in there. This is important information as it tells me about the types of bacteria that are living inside the animal. If there are lots of friendly bacteria species, the animal is probably healthy but if there are lots of harmful species then the animal could get sick. I hope that made sense and that you found it interesting too! (It’s ok if you found it a bit gross too!).

Comments

  • Photo: Chris

    Chris commented on :

    I personally haven’t had to, but some colleagues of mine have – it’s not normally something we do so it was an interesting day to say the least. Unlike Felicity who has trying to identify bacteria in the samples, we were looking for drug metabolites.

    When you take a drug, your body starts a process called “metabolism” which removes it from the body. Your body does this to protect itself – many drugs can have dangerous effects. Usually “metabolism” results in the drug being changed by your liver (“metabolised”) into a form that allows the body to get rid of it. The drug “metabolites” are then filtered out through mostly in your pee, although you they are also removed through your hair, sweat and yes – poop!