If you are interested in figuring out what the top-rated microscopes on the market are, you can check it out here. However, if you simply want to understand a bit more about the various types of such devices that are currently being used and which one to choose based on your needs, then this article is the one for you.
Many people have in mind the image of the standard compound microscope when they think about these devices, but the truth is that there are plenty of other models out there, each one designed with specific needs in mind. For instance, if you are planning to use a microscope on the go, you are not going to use a compound one that can be difficult to transport.
On the other hand, if you are working in lab conditions, and you need to rely on the accuracy of your readings, then you are not going to use a portable microscope that has a high chance of being less clear than a standard one.
With this being said, it’s important to have an overview of the main types of microscopes, so that you’ll know exactly what you need the next time you want to purchase a new one. Of course, the prices can vary greatly as well, so it’s always a good idea to know what you are after in terms of characteristics, whether you need greater resolution or higher magnification.
If we’re going through the various types of microscopes, there’s no way not to mention the simple microscope, which is the initial device that led to everything that we have today in terms of these handy devices. Created in the 17th century, the simple microscope was an invention of Antony van Leeuwenhoek.
He essentially combined a holder for specimens with a convex lens and got what could be today seen as a steady magnifying glass. On the other hand, this device did have a magnifying power between 200 and 300 times, which proved to be enough for van Leeuwenhoek to see different shapes in red blood cells and to observe plenty of other biological specimens.
Of course, the simple microscope is no longer used today, as there are so many other devices that can get this job done much better. Plus, the introduction of another lens also led to the creation of the compound microscope, which is much more powerful and, thus, useful.
Since we’ve already mentioned it in this article, it’s only natural to take a look at the compound microscope next. This device includes a second lens that further magnifies the initial image obtained with the help of the first lens. The result is a much better magnification which allows its user to observe in more detail the specimen.
Compound microscopes have some particularities as well, namely that they can be either monocular or binocular. Moreover, the specimen is lit using a light placed underneath, which is why they are called bright field microscopes. In terms of images rendered, these microscopes have a magnification power of 1,000 times, so they can definitely allow identification of individual cells.
On the other hand, the image’s resolution tends to be a bit lower, so that’s one of the downsides of choosing this type of microscope. It’s true that compound models are extremely useful and relatively cheap, which is why they are used in plenty of schools and research labs, so they can definitely help in a wide range of tasks.
Botanists are also known for using compound models, as they can easily study things such as plant cells and various parasites or bacteria. Forensics labs can also put these microscopes to good use, given that the devices are able to provide help in identifying various drug structures.
If you are looking for an item that can help you see various objects up close, while still being able to manipulate them during the observation process, then you want to take a look at stereo microscopes. These are also known as dissecting devices, and they provide a magnification that goes up to 300 times.
While this may not seem very high, these units are still very helpful, if you need to take a look at objects that are too large to require slide preparation, as is the case with compound microscopes. Stereo microscopes can ensure clear viewings of surface textures, so they are successfully used for medical and biological applications.
Another category of users that can definitely enjoy the benefits of stereo microscopes consists of those who work with electronic devices, watches, or circuit boards.
What makes confocal microscopes different from their stereo or compound counterparts is that they use laser light for observation, and the samples need to have been dyed beforehand. The two former types of microscopes that we’ve looked at use regular light for viewing purposes.
In the case of confocal microscopes, the samples need to be correctly prepared, placed on slides, and then inserted, and the dichromatic mirror included in the device’s construction helps in producing a digital magnified image that appears on a computer screen.
These microscopes work great for producing 3D images, given that operators can assemble multiple scans in order to get a clear view of the subject. While these units come with a high magnification power, just as compound models, the resolution is much better, which means that clear viewings are ensured in those cases in which fine precision is required.
In terms of how they are being used, confocal microscopes are quite popular for studying cell biology, as well as for a wide range of medical applications.
Scanning Electron Microscope
Also known as SEM, the scanning electron microscope is a special type of device because it uses electrons in order to form images, as compared to using light as the previous types of devices do. Of course, there are some significant differences in terms of the way it works, such as the fact that samples are scanned in near-vacuum conditions with this type of device.
This means that they need to be specially prepared for the process, the first step being one of dehydration, followed by a coating one in which a very thin layer that consists of conductive material is added, gold being one such example.
Once the sample is properly prepared, it’s introduced in the dedicated chamber, and the SEM uses it to produce a 3D image on a computer screen, this also being black-and-white. Given that the operator has ample control over the level of magnification, which means a lot more versatility in terms of readings, SEMs are mostly used in medical, physical, and biological sciences.
Since we’ve talked about SEMs, it’s a good moment to mention transmission electron microscopes as well. Also known as TEMs, these devices work in a very similar way to SEMs, but the image they produce is a 2D one, so they work better for objects that have a certain degree of transparency as well.
Of course, TEMs also have a wide range of applications, from medical and biological ones to forensic analysis and nanotechnology.
We’ve already looked at some types of microscopes that render images directly on computer screens, but it’s a good idea to take a closer look at what digital models have to offer. Before we go into the details, it’s interesting to note that the first digital microscope was invented in 1986 in Japan.
Today, there are plenty of models that use the power of this technology to bring images directly onto computer screens so that researchers and scientists can clearly see all the necessary details. Digital units usually connect to a computer using a USB cable, and moving images can be captured without too much trouble as well.
Of course, there are plenty of applications for microscopes within scientific organizations and communities, but given that digital devices are becoming increasingly more affordable, there is a wide usage among hobbyists and within schools that should not be neglected.
For schools and learning purposes, the easiest-to-use type of microscope one can try out is the digital USB computer one, which can be connected to a laptop right away and provides very quick readings. While the specimen doesn’t need to be prepared in a specific way, the results are less clear in terms of magnification and resolution.