What Magnification Do You Need To See Bacteria?
A microscope magnifies a small object so that details that would otherwise be invisible to the naked eye can be seen. Optical microscopes, which use visible light focused through lenses, are the most common type of microscope.
A microscope has two different types of lenses. The objective lens closest to the slide creates an enlarged and upside-down image of the sample.
The eyepiece is portrayed by the second set of lenses. The main purpose of the eyepiece is to magnify the bacteria in your sample so you can examine them more thoroughly.
If the objective lenses that come with it are of poor quality, no amount of eyepiece magnification will be able to make the picture of what you see clearer.
Why Bacteria Are Difficult to See
Bacteria range in size from spheres to rods to spirals, with a diameter of 0.2 um and a length of 2-8 um. Bacteria change color when they are present in a colony.
For a variety of reasons, bacteria are difficult to see under a bright-field compound microscope:
They’re small, so seeing their shape requires excellent optics to resolve them properly.
At high magnification, floating bacterial cells float in and out of focus, especially if the water layer between the cover glass and the slide is too thick.
They are colorless: Bacteria will only show their color if a colony is present. On the slide, individual cells are visible. Only if the condenser iris diaphragm is closed will regular bright-field optics reveal the bacteria. This is because the water and bacterial cells have different refractive indexes.
Difficult to distinguish between bacteria and small dust and dirt on the slide: An untrained eye may have difficulty distinguishing bacteria from small dust and dirt on the slide. Some bacteria clump together, making individual cells difficult to see.
What Magnification Do You Need To See Bacteria?
Here’s a quick rundown of what your microscope can see at different magnifications. You’ll be able to tell which ones are best for looking at bacteria and conducting experiments.
At 100x
At a magnification of 100x, you’ll see what looks like small dots. These dots are bacteria, but we’re still a long way from being able to properly examine bacteria. One advantage is that at this magnification, the depth of field remains reasonable and you can see the entire specimen. Currently, focusing is not a problem.
At 400x
At 400x, you can begin to look at bacteria in any way you want. Cell divisions and even chromosomes will be visible to you. Bacteria can also be seen, and their shape and other characteristics can be observed. You should be aware, however, that you will need to become proficient with the focusing knob as you will not be able to maintain a steady image for long.
At 1000x
Ultimately, you’ll need a magnification of 1000x to properly observe bacteria. However, keep in mind that your unit should have excellent stabilization capabilities. At this magnification, losing focus is easy, which is why any microscope will not suffice. To get better resolution, you should also use immersion oil.
See Also
- 7 Best Microscopes for Microbiology
- Best Budget Handheld Microscopes for Kids
- Best Microscope for Teenagers
Final Thought
Observing bacteria under a microscope is similar to observing any other specimen under a microscope. Bacteria, on the other hand, are invisible to the naked eye and require a microscope with a high magnification to see.
Higher magnification is achieved by compound microscopes, which is necessary for viewing bacteria and other small microbes.
Without a doubt, electron microscopes are ideal for studying bacteria. They are, however, primarily used by professionals and are more costly than their compound counterparts