• Question: @katie How do you look at the microbes if you cant see them with your own eyes

    Asked by anon-290860 on 18 Mar 2021.
    • Photo: Katie Endersby

      Katie Endersby answered on 18 Mar 2021:

      Hi Emma! Good question! To be able to see microbes, like bacteria, you usually need a microscope! Sometimes to make it easier to see each individual cell and to be able to make out the shapes and sizes of each, you can stain the walls of the cells in a process called gram staining. You can also get a lot of information from how each bacteria grows into a colony – which is essentially a big pile of cells that gets big enough for us to see as a whole!

    • Photo: Rob Shorten

      Rob Shorten answered on 18 Mar 2021:

      Excellent question, Emma! There are a few ways. Firstly, we can use various microscopes to make them appear much larger. For example if someone had meningitis, we could take some spinal fluid, add some stains and look at the bacteria under the microscope. Next, we can grow the bacteria in liquid broth or agar (jelly) plates. This makes the numbers of bacterial far larger so that we can see them. Other ways are by looking for the genetic material (DNA or RNA) – for example, the COVID PCR detects RNA from the SARS CoV-2 virus. Finally, we can look evidence that your body has seen an infection. Your immune system will produce ‘antibodies’ to a pathogen (germ) or vaccine. For example, we measure antibodies to chicken pox in pregnant women who have come into contact with someone with chicken pox. If the woman has antibodies, it means that they’ve been infected before and we don’t need to worry.

    • Photo: Jess Buddle

      Jess Buddle answered on 19 Mar 2021:

      Hey! Im a microbiologist and look at bacteria all the time. Some of our microscopes are the size of a whole room! They zoom in A LOT.
      You can also see millions of bacteria clumoed together in a colony on a plate just with your eyes

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