How To View Microbes With A Home Microscope

For years I worked in different microbiology labs. First, I was a microbiology lab technician doing quality control at a medical supply manufacturer, then a lab manager and lab instructor at a community college, next a graduate student doing my PhD, and finally a postdoctoral researcher. Being a microbiologist became a part of who I was. But I changed directions with my career and decided to do science communication and writing full time. And inevitably, I missed working with microbes.

So, I have found ways to still feel like a microbiologist. Only my lab is at home now.

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I began to look for microbes in my daily life more often, started making fermented foods, and bought a microscope. Since I began at-home microscopy, I’ve enjoyed it immensely, so I wanted to share that with you.

A microscope makes a delightful addition to your home science tool kit. And looking at microbes at home is a fun activity that doesn’t have to cost a ton of money. From this post, you will learn what type of home microscope will suit your needs based on the microbes you’d like to see, what accessories and tools are useful to go with it, and how to do a fun activity with your microscope.

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This post contains affiliate links — see my disclosure policy.

Types of home microscopes

There are many different microscopes that you can buy that are intended for looking at different sized organisms and objects and can be stationary or portable. Many affordable microscopes are appropriate for viewing only larger microbes. Those are stereo or dissecting microscopes with a magnification usually between 10-100X, or portable microscopes like pocket microscopes (this one comes recommended by a friend of mine – Carson MicroBrite Plus LED Lighted Pocket Microscope up to 120X) or the Foldscope (up to 140X).

On the other hand, compound microscopes are best for looking at all types of microbes down to bacteria. Some, however, are better than others. The magnification for most compound microscopes will be up to 1000X to 2500X.

Two features that matter for image quality and ease of microscope use

I found that two features matter for a home microscope if you want to view small microbes such as bacteria: a mechanical stage and an Abbe condenser.

The mechanical stage is crucial for hunting for microbes because you move the slide around constantly to search for them. They can be anywhere on the slide, and when you get up to a higher magnification, you’re looking at a tiny portion of the slide and will need to make small adjustments. But if you have to move the slide by hand, it’s challenging to make those fine adjustments. With a mechanical stage, you can do these fine adjustments, moving the slide with a couple of different knobs that allow you to move it forward and backward and side to side.

Mechanical stage of the Swift SW380B. Photo by Justine Dees.

The Abbe condenser is really important for actually getting a crisp image of most microbes and even to see bacteria well at all. It matters most at higher magnifications (400X and above). An Abbe condenser is below the microscope, so you will be able to tell that it’s there when you see a large black circular object under the stage. The way I discovered the need for an Abbe condenser and mechanical stage was when I initially purchased a less expensive microscope (TELMU Microscope 40X-1000X) without realizing it lacked these features. After hunting for some bacteria from my kombucha (see a photo here), I was unable to get a clear image and frustrated about manipulating the slide manually. So, I promptly returned it. If you don’t care about looking at bacteria, though, and only want to look at larger microbes, you may opt for a microscope without an Abbe condenser. However, the mechanical stage is still handy for microbe hunting.

Abbe condenser of the Swift SW380B. Photo by Justine Dees.

Choosing your microscope based on the size of microbes you want to see

The type of microscope you buy will depend on the size of microbes you want to see (check out this other post about different types of microbes). You can look at eukaryotic microbes, which are usually much larger than bacteria, with a less expensive microscope. You can even go tardigrade (water bear) hunting with a dissecting microscope or a portable microscope (pocket microscope or a Foldscope) because you can see them at 100X magnification. However, you will get a better view at 400X.

However, if you are like me, and want to hunt for bacteria, then you’ll want to opt for a microscope with a magnification up to 1000X and an Abbe condenser to get a good quality image. A mechanical stage will also make your life a whole lot easier, so you don’t have to move the slide by hand.

Microbes of different sizes (top, bottom right, then bottom left): tardigrade (400X), kombucha yeast (1000X), sauerkraut bacteria (1000X). Photos by Justine Dees.

My home microscope – Swift SW380B

If you are wondering where to buy a good home microscope, Amazon has many different types to choose from. I absolutely love my microscope. So, what I’ve found to be the best microscope for home use is the Swift SW380B (40X-2500X Magnification). It is considered suitable for hobbyists, students even up to the college level, and clinicians. Check out my home microscope here.

The microscope I use and recommend, the Swift SW380B. Photo by Justine Dees.

The magnification goes up to 2500X, but I found that I don’t get as high quality of an image at 2500X as I do at 1000X. It’s not even essential for it to go up to 2500X. So, you could get another microscope with an Abbe condenser and mechanical stage with 1000X magnification and still be satisfied with it. But I’m pleased with this one.

It has ultra-precise focusing that allows you to focus in and out of the different planes of an object and easily stop on the section you think looks the best or make a video of you focusing in and out of it. I noticed how neat this was when I looked at diatoms, a type of algae (check out this other post about algae). They have these stunning glass structures, and if you focus in and out of the cell, you can see the variation in the structure. In a particular plane, you may not see all of the intricacies, but in another, you can.

Diatoms from pond water. Photo by Justine Dees.

Microscope accessories

Here are some accessories I recommend purchasing along with your microscope. These items will help with preparing your samples and viewing microbes down to bacteria.

If you’d like to take photos of your microbial findings (I love to share my images on Twitter and Instagram and use them here on the blog), you will want to also get the smartphone camera adapter for this microscope. Also, looking into the eyepieces of a microscope can cause your eyes to get tired. But you can avoid using the eyepieces all together and basically turn it into a digital microscope by using a smartphone camera adapter. Get the smartphone camera adapter mount here.

Smartphone camera adapter for the Swift SW380B. Photo by Justine Dees.

This camera adapter mount is specially designed for this microscope, and it fits the 10X eyepiece. If you want to go up to a magnification of 2500X, meaning you’ll use the 25X eyepiece, this adapter will be too large. But I’ve seen people fill in the gaps with something like cardboard.

To prepare your own samples, you will want to buy microscope slides and microscope cover slips — the ones I use come together as a set. Get microscope slides and cover slips here.

If you plan to look at bacteria on 1000X magnification, you will use immersion oil. If you’ve never done this before, here’s how: first, you focus on your sample on the lower-powered objective lenses, then you take a drop of oil, place it on the slide, and then move the 100X objective lens onto the slide touching the oil. Once you are done using the oil, you do not want to move back to the 40X objective lens because it should not touch the oil.

The Swift SW380B (40X-2500X Magnification) microscope comes with a small bottle of immersion oil, and that bottle will likely last a long time. But I’m still going to suggest some immersion oil for you in case you run out and need to buy some more. I recommend immersion oil type A rather than type B. Immersion oils differ based on their viscosity, and immersion oil type A is less viscous than B and therefore will trap air bubbles less easily. So it’s suitable for the budding microscopist. Get immersion oil here.

If you plan to use immersion oil, you will also need lens paper to clean the oil off of the 100X objective lens because it actually touches the oil. You should clean the oil off every single time you use the microscope under immersion oil. Get lens paper here.

Sample collection and preparation tools

For sample collection, I use Eppendorf tubes, which are tiny snap cap tubes, and disposable plastic cups.

I like to take Eppendorf tubes with me when I go hiking to collect microbes I find, like a little piece of a slime mold, a tiny mushroom, or a piece of lichen. I usually simply grab a stick to pick up the sample and place it in the tube. Get Eppendorf tubes here.

Sample collection and preparation tools (left to right): plastic cup, transfer pipette, and Eppendorf tube. Photo by Justine Dees.

Disposable plastic cups are great for collecting water and water with sediments. And I found that it makes scooping water easy. Get plastic cups here.

An item that makes sample preparation easy is transfer pipettes. You can draw up some pond water or other liquid sample and place it onto the microscope slide. Get some transfer pipettes here.

Scroll to the bottom of this post for a list of all of the recommended supplies.

Microscope activity – Look at pond water

Materials

Plastic cup
Transfer pipette
Microscope
Slide
Cover slip

How to look at pond water under the microscope

A classic microscope activity is to look at is pond water, and it is extremely satisfying because you can find so many different microbes and tiny organisms. Every pond is different. I’ve found that one pond will have very few microbes and then another pond will be filled.

Using your plastic cup, scoop up some water and a tiny bit of sediments.
Place the lid on your plastic cup and head back to your microscope.
Using a transfer pipette, place a few drops of pond water and a tiny amount of sediments onto the slide.
Place the cover slip over the water. If you hover over the slide with the cover slip and drop it, you may end up with bubbles. (I don’t mind bubbles because sometimes the image looks different and cool.) If you want to avoid bubbles, you can lean the cover slip on the slide and lower it from an angle. Congratulations, you made a wet mount!
Turn your microscope on and clamp your slide on the stage.
Start with the 4X objective lens and get it into focus (40X total magnification).
Move to the 10X objective lens and focus it. Here you may begin to see some things moving. Start to hunt for microbes (100X total magnification).
When you find something interesting, move to the 40X objective lens to get a closer look (400X total magnification).
Take a photo and share it with me!

Pond microbe: freshwater algae *Pediastrum duplex*. Photo by Justine Dees.

Deepen your exploration of the microbial universe!

My ebook, “Joyful Microbiology Activities,” provides 10 engaging, DIY experiments to ignite your curiosity about the unseen world of microbes. Get your copy today!

Other ideas for microscope activities

Here are a few other ideas for microbial samples to view on the microscope.

Microscopy Bucket List:

Mold (bread or cheese)
Sauerkraut
Kombucha
Sourdough starter
Lichen
Mushroom spores
Tap water
Kitchen sink residue
Puddle
Moss (look for tardigrades – see this post on how to find a tardigrade)
Yogurt
Swamp
Stream
Shower – anything growing? Pink stuff? (Learn what the pink stuff is here.)

Final thoughts on at home microscopes

So there you have it: an introduction to at-home microscopes, what to look for, which one to buy, what accessories to go with it, and an activity to try. This is the microscope that I recommend for looking at microbes down to bacteria.

I can’t wait to hear all about your microscopic adventures. Share them with me on social media or send me an email! I know you will find some amazing microbes out there. Happy microbe hunting!

Links to recommended microscope and accessories

Microscope

Microscope accessories:

Sample collection and preparation:

SWIFT SW380B 40X-2500X Magnification, Siedentopf Head, Research-Grade Binocular Compound Lab Microscope with Wide-Field 10X and 25X Eyepieces, Mechanical Stage, Ultra-Precise Focusing

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Swift SW380T 40X-2500X Magnification, Siedentopf Head, Research-Grade Trinocular Microscope Compound Lab with Wide-Field 10X/25X Eyepieces, Mechanical Stage, Ultra-Precise Focusing, Camera-Compatible