• Question: Can you see bacteria cells and viruses under a microscope

    Asked by anon-181914 on 18 Jun 2018.
    • Photo: Alex Haragan

      Alex Haragan answered on 18 Jun 2018:

      I certainly see bacteria under the microscope!
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      There are many different types of bacteria – and they have different shapes. If you are growing cell cultures it is very upsetting to look and see bacteria as you’ll probably have to discard them and start again,.
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      Most of the work I do diagnosing patients involves looking at tissue under a microscope. So mostly I am looking at human cells – but the cause of a problem might be infectious. Sometimes I see things that are suspicious for bacteria – and if I can’t see them under the normal stains I might get a special stain done that makes it easier to spot bacteria.
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      Viruses are typically too small to see with normal (light) microscopes – (though you can see all sorts of tiny things with other devices like electron microscopes).
      However – human cells often have tell-tale signs of viral infection, some of which only occur in instances of specific viral infection.
      For example, CMV (cytomegalogvirus) makes cells (cyto) look big (mega) and they have specific changes called Cowdry bodies that make the cells look a bit like owl’s eyes.
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      The world under a microscope is a fascinating place!

    • Photo: Joey Shepherd

      Joey Shepherd answered on 19 Jun 2018:

      Yes, you can absoloutley see bacteria under a microscope. As Alex said, you can use special stains to help you to see them more easily but you can see them without stains as well. Some bacteria can swim and it’s fascinating to sit and watch them swimming about under the microscope!

      Viruses are much much smaller than bacteria so you can’t see them under a normal microscope, you have to use a special type of microscope known as an ‘electron microscope’. But there are ways you can tell if you have viruses – for example, some viruses known as ‘bacteriophage’ actually attack bacteria and not human cells, so you can grow bacteria and if they are infected with bacteriophage you will see holes forming where the bacteriophage have killed the bacteria. There’s one particularly interesting looking ‘phage called a T2 bacteriophage, it looks like a little robot or moon lander – look it up, it’s amazing!

    • Photo: Claire Donald

      Claire Donald answered on 19 Jun 2018:

      I use microscopes to look at my viruses all time. As Alex and Joey said, you need a very powerful microscope like an electron microscope to get detailed pictures of viruses. My department recently got a very large grant to buy a ‘state of the art’ electron microscope which costs £1,000,000s. I would be too scared to use it in case I broke it!

      Mostly I use a much less sophisticated kind of microscope called a florescent microscope. If I make a virus that can fluoresce with different colours, I can follow it inside cells and see where it goes and what it does. The pictures can be pretty with all the florescent colours but are much less detailed than with an electron microscope.

      I also need to use a different microscope for mosquito dissections. These microscopes just use normal light and magnify the view of the mosquito. No way I could dissect mosquito salivary glands without it!

      You can now buy microscopes that attach to your phone so you can see the microscopic world wherever you are. Check out ebay!

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