We cannot see everything through our naked eyes. That’s when we need instruments like a microscope to look into the depth. The microscope is all about magnifying and resolving power. This is equivalent to its ability to magnify the objects and measure the distance between two separate objects, respectively. The concept of microscope has been with us since the late 16th century. Today, it has applications across various fields. In the scientific and research fields, it is used to study cells and living organisms. It is because of the invention of the microscope, we came to know about the existence of microorganisms.
In forensic science, it is used to identify and compare samples, which helps in solving crimes. And the list goes on. Based on the features, we have different types of microscopes. In this discussion, we will look at some of them in detail.
Microscope Definition
A microscope is a scientific instrument that allows users to view an enlarged image of any smaller object. It reveals details that are almost invisible to the naked eye. Most common microscopes rely on lenses that reflect light onto an object to enlarge it. Microscopes are mostly associated with the scientific field and are found in laboratories. The study of investigating smaller objects using a microscope is called microscopy, which literally translates to being invisible to the eyes unless using a microscope.
What does the future hold for microscopes?
Microscopes are used in numerous scientific fields. It is also very important to the medical science field. It is one of the foremost tools used for viewing and analyzing biological samples for making medical diagnoses. Over the years, microscopes have also advanced and are now capable of many things deemed impossible a few decades ago.
Even from an economic point of view, the current global market for microscopes is valued at around $3 billion and is expected to grow almost 5% by 2030. It will also drive innovations in the field, as the 4D microscopy mentioned in the video below shows:
Recent trends in microscopy
We have seen a rapid advancement in microscopy, which is often accompanied by an improvement in the microscope itself. Today, there are several types of microscopes available for specific purposes. Let us then look at some of the recent trends in microscopy:
Involvement of AI
Yes, microscopes have not been shy to employ the current AI technology. By relying on a newly developed confocal platform, microscopes have used AI to become more powerful and offer enhanced images. The platform otherwise known as multiview confocal super-resolution microscopy is now capable of using deep learning algorithms to collaborate with other imaging systems to empower the resolution of the images up to 10 times.
Live-cell imaging
Another revolution in the market has come in the form of an advanced brightfield live-cell imaging system. A Dutch company by the name of CytoSMART Technologies is responsible for it and has termed the microscope Lux3 BR, which comes with a powerful 6.4 MP CMOS camera and operates as a standard cell culture incubator.
It is a huge step in medical science as it allows researchers to experiment with cell cultures without worrying about temperature changes, airflow, or other culture conditions, thus resulting in accurate and reliable data.
Here is a quote by the CTO of CytoSMART Technologies regarding their latest innovation:
“We are very excited to expand our label-free microscopy solutions for live-cell studies. For cell biologists who want to incorporate live-cell imaging into their workflow, the resolution of live-cell imaging microscopes may be too low for accurately quantifying complex read-outs, such as cell tracking or differentiation processes,”
CytoSMART Technologies CTO, Jan-Willem van Bree.
What are the Types of Microscopes Available?
There are numerous types of microscopes available on the market. Listing each one of them might be a difficult task. However, we are going to take a look at the most important types of microscopes you should know –
1. Simple microscope
As the name suggests, this microscope is quite a simple one, plainly magnifying the objects for you. This way, you see an enlarged image of the object at hand. It uses a double convex lens, forming a magnifying image when the object is placed within its focal length.
This means, if you place the object closer to the lens, then you can see a more magnified image. But it uses only a single lens, so the magnification capacity is just 10X. At the time of its invention, it was used to study the microbes occurring in freshwater. Today, it is mainly used to study biological specimens in the lab. Other than this, it is used in repair workshops to see the tiny parts of the object.
Features
- Uses double convex lens
- Single lens
- Up to 10X magnification
- Used for biology and repair
2. Compound microscope
Does the name compound microscope ring a bell? The chances are you might have used this microscope in your schools or colleges. The compound microscope is chosen when the samples to examine needs to be highly magnified. It uses two or more convex lenses to magnify the images further, and have a magnification capacity ranging from 40X to 1000X.
Because it can magnify the objects 1000X, it is used to study cells. Additionally, it has its own light source, and the multiple lenses show a significant amount of details. Also, it is inexpensive and easily available. Thus, it is widely used for academic purposes.
Features
- Multiple lenses
- 40X to 1000X magnification
- Ideal for cells
- Academic use
3. Polarized microscope
Starting with the basic, polarized light is the light wave that vibrates only in one direction. Based on this concept, polarizing microscope functions. So what happens here is the behavior of the cell components is observed under polarized light. It is beneficial as it gives clear vision and increases contrast. The polarized microscope is used to study the minerals and rocks.
Additionally, it is portable, meaning it can be taken to sites for examination. Basically, this microscope has a polarizer and analyzer that highlights the density and color difference on the surface of the sample. This makes it suitable to study birefringence materials. It is commonly used in pharmaceuticals, pathology, and geology.
Features
- Uses polarized light
- Increases contrast
- Studies minerals and rocks
- Portable for geology
4. Electron microscope
In the other types of microscopes that we studied till now, light was used to view the image. The electron microscope is an exception in this case, as the electron beams are used as an energy source. It can magnify the objects in nanometers. These electrons pass through the specimen and display a digital image on the monitor.
Also, it has the highest resolution. But on the flip side, the samples are destroyed by the electron beams. So studying a live specimen is not always an option here. It is further classified into two types: Transmission and Scanning electron microscope.
Transmission electron microscope (TEM)
TEM generates a highly magnified image using a beam of electrons, which passes through the specimens. This is why the ultra-thin slices of specimens are used so that the electrons can pass through them and receive information. A projection image is then generated. It is used to study the interior of the cells. Unfortunately, the requirement of thin samples limits the use of TEM to experience and well-trained users.
Scanning electron microscope (SEM)
SEM is used to generate detailed images of the surface of the specimen. It is used as obtaining these images is not possible by TEM. Here, the electron beam is scanned onto the surface of the specimen to determine size and composition. This is done in a raster pattern. It is also used to detect contamination on the surface of the sample.
What makes SEM different from TEM is that, here, you can get 3D images, whereas TEM only generates 2D images. There is no denying that the 3D images are more useful to interpret the results.
Features
- Uses electron beams
- Nanometer magnification
- Destroys samples
- Includes TEM and SEM
5. Stereo microscope
If you want to get the feel of holding a sample in your hand, then you might want to consider the option of observing it under a stereo microscope. The reason is the stereo microscope is used to get a 3D view of the object. And the image formed here is upright. Another name of this microscope is dissecting microscope.
Since we are talking about the 3D view, the separate optical paths for each eye come as no surprise. Here, the magnification ranges from 10X to 50X. Mostly, it is used to study opaque objects such as flowers, insects, fossils, and many more. It is also used in educational institutes for dissection projects. Furthermore, pathologists use this microscope to perform dermatological examinations.
Features
- Provides 3D view
- Magnification 10X to 50X
- Opaque objects and dissection
- Dermatology exams
6. Fluorescence microscope
First things first, by exposing fluorescent dyes to ultraviolet rays, we can convert the invisible light that is the shorter wavelength rays to visible light that is the longer wavelength rays. So, in a fluorescence microscope, the specimen is stained with fluorescent dye. You may now wonder why is that the case?
As mentioned, when the fluorescent substance is illuminated, it emits fluorescent light with a longer wavelength, making the sample more visible. This makes studying specific cells in the microbial population feasible. Likewise, it is used to observe live cells. It also provides high-quality 3D images of the cells. So, the researchers can also easily label the structures within the cells.
Features
- Uses fluorescent dyes
- Converts UV to visible light
- Studies specific cells
- High-quality 3D images
Comparison of Different Types of Microscopes
We have analyzed the microscope types in detail. Now, to quickly find which one you are looking for, let us compare the different types of microscopes:
| Types of Microscope | Description | Magnification | Light Source |
|---|---|---|---|
| Simple | Uses a single lens | 300x | External |
| Compound | A combination of multiple lenses | 2000x | Reflection |
| Polarized | Relies on polarizers to view birefringent elements | 1200x | Transmission of polarized particles |
| Electron | Electrons are used for an ultra clear imaging | 10,000,000x | Electromagnetic lenses |
| Stereo | Offers 3D imaging | 300x | Reflection |
| Fluorescence | Detects fluorescent molecules. | 2000x | Fluorescent Light |