What Kind of Microscope you Need to See Sperm
Sperm cells are nearly invisible, even under a microscope. Special types of microscopes must be used when looking at sperm.
- Phase Contrast Microscopes: The gold standard for observing sperm in labs. This type of microscope makes sperm cells pop out from the background. The downside is that Phase Contrast Microscopes are very expensive, starting at $5000.
- Darkfield Microscopes: Darkfield Microscopes enhance contrast by making samples appear colored on a black background. Unfortunately sperm are almost as difficult to see on a Darkfield Microscope as on a basic, unmodified brightfield microscope
- Modified Brightfield Microscopes: By modifying a basic, inexpensive brightfield microscope, you can view sperm better than with Darkfield Microscopes. Although you wont get the same quality as on a Phase Contrast Microscope, a Brightfield Microscope is substantially cheaper (around $200) and far easier to use.
In this article we will focus on how to set up the Modified Brightfield Microscope method for observing sperm.
The Modified Brightfield Microscope Method
On a normal Brightfield Microscope, sperm will blend in with the background and be invisible. There are two critical modifications to do that will make sperm visible.
- Control the Illumination Angle: On a typical brightfield microscope, you can control the angle of light that hits your sample using a condenser. When the condenser is all the way open, more angles of light hit the sample. When the condenser is closed, only a shallow angle of light hits the sample. In this case, we want to increase contrast of the sample by decreasing the angle of the light. You can do this by either closing your condenser all the way down, OR, if your microscope doesn’t even have a condenser, that is perfect. Not having a condenser effectively does the same thing as having a condenser that is all the way closed.
- Use a Camera: The problem with lighting up your sample with a shallow angle of light, is that although your sample will be high contrast, the floaters in your eye will suddenly become visible, and make it almost impossible to see the sperm. The same reason that the shallow angle of light makes normally invisible sperm visible, is the exact same reason why the shallow angle of light makes the normally invisible floaters in your eye suddenly visible. Using a camera instead of your eyes to view the sample is critical. Not only do cameras not have floaters, but they are more adept at picking up and enhancing small differences in brightness than our eyes are.
What Microscope to Buy to Look at Sperm
Here are some more options from Amazon that will also work for observing Sperm. Note that buying a camera along with the microscope is critical for this to work!
https://amzn.to/48U7Gul (m120C)
https://amzn.to/3UVtvpU (b120c)
https://amzn.to/48MrbF6 (5MP Camera)
DO NOT buy a cheap digital microscope that claims it can magnify 1000x and try to look at sperm with that. It will not work, and you will be sad.
In order to see sperm, AT A MINIMUM, your microscope needs:
- A 4x and 10x Compound Objective: These are what actually does the high resolution magnification of your sample. 4x and 10x are the two magnification levels that will be useful to you.
- A Transmitted Light Illumination Source: The light should shine through the sample, not reflect off of it.
- A Camera: Without a camera, the floaters in your eyes will make the sperm very difficult to see and you will get eye strain.
Now that I can see Sperm, What’s Next?
- How to Set up a Microscope to See Sperm: The next step if you own a microscope and want to look at your sperm at home. (link coming soon!)
- The Comprehensive DIY Guide to Assessing Male Fertility at Home: Our ultimate technical deep dive into evaluating your own fertility at home.(link coming soon!)
Q&A
Q: Can you use a smartphone microscope or a pocket microscope to view sperm?
A: No. The optical setup of a pocket microscope is not high enough magnification nor optically set up to be able to observe highly transparent cells such as sperm.
Q: What other supplies should I get to look at sperm at home?
A: If you already own a microscope or choose not to purchase our kit, you could just copy the basic supplies that are included in our kit and source them elsewhere. The fixed volume micropipette could be switched out with a regular pipette. The micropipette is only important if you are trying to estimate sperm count or evaluate sperm motility.