Conventional microscopes have a vertical configuration. This means that the light source is at the botton of the structure. Next, there is the stage where the sample is placed and finally the head with the objectives and the eyepiece on top. This is the most common configuration, but not the only one.
There are also inverted microscopes. These microscopes have a totally opposite configuration to that of the upright microscope. The sample is illuminated from the top and the optical elements are located under the stage. With this type of microscope, it is possible to observe samples placed at the bottom of a container. This is very useful to keep them hydrated and thus be able to observe live samples and biological processes that last days.
Digital microscopes are those that capture a digital image of the sample. This is accomplished by connecting a digital camera instead of the eyepiece. There are digital microscopes with different configurations. Usually, they must be connected to the computer in order to transmit the images and then view them. It is also true that there are digital microscopes with a built-in screen. These allow you to view the sample on the screen and store images that can then be transmitted to a computer via a USB connection or SD card.
A special type of digital microscopes is the USB microscopes. These microscopes consist solely of a high-magnification lens and a digital camera. The magnification that is achieved is limited compared to a conventional light microscope. Even so, they are very versatile and useful instruments for observing everyday objects. USB microscopes are connected to the computer via a USB connection and allow images of the sample to be saved.
The stereoscopic microscope is a type of microscope that allows you to observe the sample in a three-dimensional way. These microscopes are always equipped with two eyepieces. The image of the sample that reaches each eyepiece is slightly different so that when they are combined, the 3D effect is achieved. This effect could not be achieved if the sample was viewed with only one eyepiece.
The magnification achieved with the stereomicroscope is lower than that achieved with a conventional optical microscope. However, conventional microscopes only allow two-dimensional observation of the sample. Stereomicroscopes are widely used in applications where the sample must be manipulated while observing. For example, for the assembly of circuits or clocks.
Other types of microscopes
In addition to the microscopes previously presented like Mighty scope, there is a multitude of additional microscopy techniques optimized for specific sample types. Some of the microscopes are:
This is a type of fluorescence microscope. Instead of globally illuminating the sample, it is illuminated point by point in succession and the image is reconstructed at the end of the process. This process of scanning the sample is similar to that of scanning electron microscopes. This type of the microscope was invented by Marvin Minsky in 1957.
Dark field microscope
This microscopy technique consists of illuminating the sample obliquely. In this way, the light rays that reach the objective do not come directly from the light source but have been first scattered by the sample. This technique allows you to see samples that would not otherwise be visible due to their transparency. It also has the advantage that it does not require staining the sample to increase its contrast and be able to observe it.
Phase contrast microscope
Light travels at different speeds depending on the medium of propagation. This property is used in the phase-contrast microscope since light passes through the sample with different speeds in different sections. This effect is amplified to generate the image of the sample. This technique does not require the use of dyes and, therefore, living cells can be observed. The phase-contrast microscope was invented by Frits Zernike in 1932 and was awarded the Nobel Prize in Physics in 1953.