Hello Microscopy
They say curiosity knows no bounds. When unable to observe the myco-microcosms my curiosity hit a bit of a roadblock. Being a visual learner, I wanted to witness every stage in a fungus's life cycle. Macro photography with my trusty 18x lens has captured many interesting shots of a mushroom's morphology, but it was incapable of the magnification needed to glimpse the world of spores, hyphae and bacteria. What I needed was a research grade microscope with the ability to capture observations. After months of saving, I invested in a microscope that would fit my needs. Little did I know it would open the floodgates to my curiosity.
Microscopy Observations
Go basidium or Go Home
My first goal was to observe a basidium. The basidium is the specialized type of hypha that develops spores in the basidiomycota division of fungi. The cell is vital in the development of fungi and there is a lot of could learn from it.
Within a short while of collecting a gill sample, I was examining a perfect basidium at 400x magnification. A lucky find for a novice! Unfortunately, I was unable to capture the exciting rookie find, because my camera adapter hadn't arrived yet. Instead, I'm sharing this photo of a basidium from a king oyster mushroom I cultivated. It appears the spores hadn't developed yet or they have already broken free.
Spores & Hyphae
There aren't many mushrooms fruiting during the winter months in Pittsburgh. To unlock the potential of my microscope, I have been observing mushrooms I've cultivated or purchased at the grocery store. This photo, taken at 400x magnification, is a gill of a common button mushroom, but after a few days of decomposition. You can see the galaxy of spores and the hyphae trying to maintain the most efficient network as the inevitable slowly comes. It is a spectacular scene of survival and chaos. With Spring around the corner, I'm hoping to share many other micro-mycology adventures with you.
Big 'ol Water Bear
With nearly a foot of snow on the ground, I assume it would be difficult to observe microbial life during the winter. During a snowy hike, I collected a small sample of moss from a snow-covered log. Returning home, I placed the moss in a small jar with some distilled water in it. Using a pipette I collected a fragment of the moss and some other debris. Then place it on a slide with a fresh coverslip on top. In no time at all, I've discovered my first microorganism, a tardigrade.
Anatomy of a Trinocular Compound Microscope
This is my Microscope. There are many like it, but this one is Mine.
Microscope Buyers Guide For Mycology
Purchasing an introductory microscope is challenging, especially if you are a novice to microscopy. My goal is to demystify the buying process by educating you with a general understanding of microscope specifications and vocabulary.
Types of Microscopes
To begin, determine which type of microscope is best suited for your needs. At the introductory level, you'll want to choose between either a compound light microscope or a stereo microscope.
Compound Microscope
Compound light microscopes offer high-magnification and are well suited for observing spores, hyphae, and most microbial life. They work by using curved lenses to magnify light passed through a transparent specimen.
Stereo Microscope
Stereo microscopes illuminate specimens from the top giving the ability to observe surface features of opaque specimens. Magnifications typically max-out around 100x, but they are ideal for studying mushroom morphology. For all the photographers out there, think of the stereo microscope as a very powerful macro lens.
Due to my inexperience with stereo microscopes, the majority of this guide is focused on the features of a compound light microscope.
The Mechanical Stage & Focusing
One of the most important features of a microscope is the stage. It is the platform where slides are placed between the optics and light source. Mechanical stages give the ability to explore the microcosm with precise movements that transition a specimen from front to back and left to right. If the stage is not mechanical, you'll need to manually move the slide to transition the view, aka the exact opposite of a good time. If you are buying a microscope for mycology purposes a mechanical stage is a vital feature.
Ensure the microscope contains a coarse and fine focusing knob, Otherwise it will be extremely difficult to sharpen the image at high magnifications.
- Coarse Focus: Roughly transitions the stage up and down, used to begin focusing in on a specimen.
- Fine Focus: Precisely manipulates the depth of focus.
Depth of Focus: the distance between the two extreme axial points behind a lens at which an image is judged to be in focus.
Simply put, as the focus knobs are manipulated up and down, the focus (sharpest layer) rolls up and down the specimen.
Carolyn Grayson created a great video demonstrating depth of focus using three different colors of tread stacked on top of each other.
Eyepeice
The eyepiece is the optics you look through.
- Common Magnifications: 5x, 10x, 16x, 20x, 25x.
- WF stands for Wide Field and offers a larger field of view.
- They slide into place, allowing for fast swapping.
- Image quality degrades as magnification is increased for most lower-end eyepieces.
- The binocular head increases depth perception giving the specimen a 3D effect.
Objective Lens
Objective lenses contain a more complex set of optics compared to the eyepiece. For that reason, they are often far more expensive. The first number on the objective is the magnification and the second number is the numerical aperture.
Larger objectives can come in close proximity to the slide, so be very careful not to crack the slide by zooming in too far. Also start your viewing at the lowest objective and slowly increase to higher magnifications.
Common types of Objective Lenses
- Achromatic: The most basic type giving a flat field of 65%, meaning the outer 35% of the image could be blurry or distorted.
- Semi-Plan: has a 80% flat field
- Plan: has a 95% flat field but are more expensive.
Understanding Magnification
While a very important aspect, the advertised magnification of a microscope can be misleading. Total magnification is calculated by multiplying the eyepiece by the objective lens. As a selling point, manufacturers want to advertise a wide range of magnifications. To achieve this they add lesser-used 25x eyepieces and 100x oil immersion objectives.
As the magnification of the eyepiece increases, the image quality typically degrades. For that reason, I barely use the set of 25x eyepieces that came with my microscope. I would show you the difference in quality, but the 25x eyepiece is incompatible with my camera phone adapter (yet another strike against it).
Oil Immersion objectives are submerged in a special oil to achieve high magnification. The oil is messy and could destroy non-oil objectives if they accidentally come in contact with the oil. Most of the time, oil immersion isn't needed, but it is very handy for mycology when observing hyphae and spores.
|
Eyepeices
Objectives
|
5x |
10x |
16x |
20x |
25x |
|---|---|---|---|---|---|
| 4x | 20x | 40x | 64x | 80x | 100x |
| 10x | 50x | 100x | 160x | 200x | 250x |
| 20x | 100x | 200x | 320x | 400x | 500x |
| 40x | 200x | 400x | 640x | 800x | 1000x |
| 60x | 300x | 600x | 960x | 1200x | 1500x |
|
100x
Oil Immersion
|
500x | 1000x | 1600x | 2000x | 2500x |
Lighting & Filters
Compound microscopes illuminate specimens from the bottom. Light from the lamp passes through the specimen, then into the optics. An LED lightsource is superior to older sources because of the low heat, magnitude and extensive life.
Most microscopes have a filter holder which allows you to manipulate the color of the specimen or background. You can find affordable sets of 3D printed filters online from places like ebay.
Darkfield
Darkens the background and lights the specimen with indirect light from the side.
Rheinberg
Manipulates the color of the specimen and background.
Oblique
The light enters from a sideways angle producing a high contrast image giving a 3D effect.
Microscope Photography
Sharing your microscopy experiences is extremely important, whether for scientific purposes or to post on social media. Now-a-days microscope photography is easier than ever. Trinocular head microscopes have a camera port (photo tube) that is designed for capturing observations, but you can still take photographs and video through a normal eyepiece with a camera phone adapter.
Camera Phone Adapter
For the citizen scientist on a budget, there are adapters that fit your camera phone. All the microscopy captures on the page were taken with a phone adapter. When purchasing ensure the adapter would work with your brand of phone and the size of your eyepiece.
SLR Camera Adapter
If you own a SLR camera, there are adapters that allow you to connect your camera to the camera port/photo tube. When purchasing ensure the adapter is compatible with your camera.
Microscope Camera
Microscope cameras are specially designed for photographing or filming your microscopy discoveries. However they tend to be very expensive, sometimes they cost more than the microscope. My suggestion is to use one of the adapters before investing in a microscope camera.
