Silicon drift detectors or Microscopes are high-tech devices that allow us to perceive the world at a whole new level. Most people are unaware that the first compound microscope was developed in 1590 by Dutch spectacle manufacturers Hans and Zacharias Janssen.
There are many types of microscopes on the market today, with light microscope and electron microscope being two of the most prevalent. It is critical to understand what they are and how they vary to ensure that your lab has the appropriate equipment for your needs.
What exactly is a light microscope?
Also known as an optical microscope, a light microscope is a type of microscope that uses light to magnify objects. It illuminates the things in vision by using light with a wavelength of 400 to 700 nm. The lenses are glass, and the picture is generated by light absorption. Light microscopes are portable and compact. They don’t function in a vacuum.
You can employ a range of specimen types, including fixed or unfixed specimens, stained or unstained specimens, living or dead specimens. It is not difficult to prepare specimens for the microscope. In most cases, it can be completed in a matter of minutes to a few hours.
The specimen can be 5 micrometers thick or thicker, and it does not need to be dehydrated before the examination. To make the specimen visible, it is dyed with various chemicals. The item is then put on a glass slide and enlarged up to 1,500 times. That may appear remarkable, but it is at the low end of what microscopes are capable of. The picture is focused mechanically by altering the lens position.
Light microscopes often have little resolving power and a poor field of vision. They display flat color images, yet it is possible to view live processes such as cell division and tiny pond life. The room in which the microscope is kept does not require any specific settings. Through the eyepiece, images are seen directly with the human eye.
Light microscopes are easy to operate and do not require high voltage electricity or filaments. There is no danger from radiation. They are reasonably inexpensive and require little upkeep.
Light microscopes are classified into the following types:
- Fluorescent microscopes: Instead of or in addition to light reflection and absorption, these microscopes use phosphorescence and fluorescence to examine specimen features.
- Phase-contrast microscopes: Change the brightness of a picture by converting phase variations in light traveling through a transparent object.
- Dark-field microscopes: Those that exclude visible light to refract it and brighten the subject against a dark backdrop.
Light Microscope uses
Light microscopes are ideally suited to the majority of fundamental tasks and are commonly seen in classrooms. Examining the following applications:
- Multicolor staining of structures in preserved and living biological samples
- Particles found within cells
- Thin tissue sections
- Fragments of glass
- Cultured living cells
- Grain limits, outlines, and edges are examples of external features.
- Organisms from the sea
- Tissues and cells mounted
- Thin germs that are not visible under normal lighting
What exactly is an electron microscope?
A beam microscope is another name for an electron microscope. Ernst Ruska, a scientist, and engineer Max Knoll created it in 1931. It employs an electron beam to enlarge things and provide a more detailed image. The pictures are created by electron transmission or scattering. Instead of glass, these have electromagnetic lenses. They are bigger and heavier than light microscopes, and they work in a high vacuum.
You can’t look at living specimens with an electron microscope. The specimen must be dyed or fixed. Preparing the specimen is more labor demanding, normally takes a high degree of competence, and might take many days. The technique often involves the use of corrosive chemicals as well as the interpretation of pictures owing to artifacts. The specimen is very thin – typically 0.1 micrometers or fewer. Only dehydrated specimens are used in this sort of microscope. To bounce electrons, specimens are plated with heavy metals and put on a copper-based metallic grid. The strength of the electric current to the lenses is adjusted to focus.
Electron microscopes offer a high magnification capability of up to one million times. They also have a high resolving power, about 250 times that of a light microscope. The resulting image gives a nice surface view as well as inside details, however, it is grayscale. Images are viewed on a zinc sulfate fluorescent screen or a photographic plate rather than directly with the eyes through an eyepiece.
Living processes, unlike those seen with a light microscope, cannot be observed. Images in transmission electron microscopy (TEM) can only be viewed in two dimensions. When using a scanning tunneling electron microscope, depth is added to create the illusion of a three-dimensional picture.
Electron microscopes must be utilized in a carefully controlled environment and microscope preventive maintenance with regulated humidity, temperature, and pressure. They also require tungsten filaments and a high voltage current of at least 50,000 volts. They are equipped with a cooling system to decrease the heat created by the high voltage current. There is a possibility of radioactive leakage.
These microscopes are extremely complicated, as well as expensive to acquire and maintain. If you need one for your lab, a leasing program can help you acquire one for a fraction of the upfront cost, allowing your budget to stretch further and bringing you what you need faster than raising funds for a large purchase.
Uses of an Electron Microscope
Electron microscopes are confined to specific purposes, such as research, due to their complexity. It is most commonly employed to analyze exterior features, such as the ultrastructure of cells and other extremely tiny animals.
A beam of electrons is moved back and forth over the surface of the object – whether it is tissue or a cell – with Semtech solutions. This generates a comprehensive three-dimensional picture of the surface.
Before imaging with TEM, the material is sliced into tiny slices. The electron beams in this approach travel through the slice rather than over the surface.
Before imaging with TEM, the material is sliced into tiny slices. The electron beams in this approach travel through the slice rather than over the surface. As a consequence, detailed pictures of the inside cell architecture are produced.