We explain what a microscope is, how it evolved and the parts that make it up. In addition, we explain its general characteristics, types, uses and more.
What is a microscope?
The microscope is a tool that allows you to observe objects and elements that are too small to be captured with the naked eye. Its name comes from the Greek “microns” (diminutive) and “scopéo” (to look), and uses the principle of refraction and reflection of light to generate a controlled magnification of the image of matter.
The microscope It was invented in the 16th century through an optical system of magnifying lenses, which has been perfected to this day, in which there are electronic variants so powerful that they allow us to glimpse the smallest objects.
This instrument allowed a deep understanding of microscopic life and thus changed the understanding of life as a whole, thus becoming an indispensable tool for modern medicine, biology and pharmacology.
See also: Photography.
First microscope
The first known microscope It was manufactured by Zacharias Janssen in 1590, who also participated in the invention of the telescope. However, there are many points of disagreement regarding the issue, since Janssen was also a known forger.
In any case, the appearance of this instrument pallowed the revelation of the microscopic dynamics of the human body and the first observation of a living cell in 1665.
Evolution of the microscope
It is said that around 1930, compound optical microscopes had reached the limit of their capabilities, which magnifications were around 500X and 1000X.
However, In the following years the electron microscope was invented, which allows magnifications of 100,000X to be reached, useful for observing the structures inside living cells. Even today, more and more powerful variants of the instrument continue to be studied.
Parts that make up the microscope
Conventional light microscopes (simple and compound) have the following parts:
- Arm. The physical support that connects the base of the microscope to the lenses and the optical viewfinder. It is also called a column.
- Base. The bottom part of the microscope, where the instrument rests and which may contain the light source (if built-in). Also called the microscope foot.
- Eyepieces. This is the name given to the lenses through which we look and receive the amplified image.
- Illuminator. Device, whether incorporated into the microscope or not, that provides the light necessary to observe the material. In the most basic microscopes, an external light source must be provided.
- Board. Platform on which the specimen or substance to be observed is located amplified. It has clips to hold it and prevent movement.
- Drum or revolver. Part of the microscope with the different optical lenses (objectives), which usually rotate to vary the magnification.
- Goals. This is the name given to the different optical lenses of a microscope, which offer different magnification measures and are usually interchangeable with each other.
- Capacitors. Lenses that focus the light ray on the observed material.
- Coarse and micrometric screws. They modulate the distance between the lenses and the observed matter, to allow greater or lesser focus according to the observer’s eye.
Microscope Refraction and Reflection
- Refraction. One of the two fundamental principles of every microscope is the refraction of light, which involves the deviation of light beams when they pass through a certain medium towards another. Calculated to obtain a specific effect through the series of microscope lenses, this phenomenon allows the image to be enlarged up to several times its actual size.
- Reflection. Similar to the previous case, the principle of light reflection is one that allows us to predict the behavior of light when it hits a body whose surface rejects it. It is the principle that operates in mirrors and allows, in the microscope, to manipulate the light beams to concentrate them on the object to be observed against the light.
Types of microscopes
There are different types of microscopes, according to the method used to magnify the images of microscopic matter, namely:
- Optical microscope (simple). The most common and the first to be invented, uses an optical lens to enlarge the image of what is observed.
- Compound microscope. A step forward from the optical (also called light) microscope, it uses a complex system of variable and combined lenses to provide different types of magnification on the observed matter.
- Digital microscope. A contemporary variant that takes advantage of computer technology to enlarge the image through very high-resolution cameras.
- Fluorescent microscope. This variant of the light microscope uses fluorescence or phosphorescence useful for specific studies of the subject.
- Stereo or dissecting microscope. It has two objectives and two ocular lenses to provide the user with a three-dimensional optical experience.
- Electronic microscope. One of the most advanced and important microscopes today, it uses electron flows to illuminate the observed matter and thus obtain magnification ranges that are impossible with other microscopes.
Microscope optics and lenses
Microscopes would not exist without the development of geowhich allows us to understand the system of relationships of light when it hits the surface of the lenses. These They can be concave or convex, depending on the orientation of their curvature, or they can be simple or complex according to the structure of their surface. In this, the microscope is very similar to the telescope.
Preparation of the object to be observed
To use the microscope, we must prepare the object to be observed, mounting it on a sheet of transparent glass called slide. It is then covered with another thinner and smaller sheet called coverslip and, if necessary, dyes or colorants are added to identify what is being sought.
Virtual microscopes
This is what it is called a novel technique for zone analysis of data from a cytological or histological specimen (cells and tissues), through a computer system that reproduces the information captured in a simulated environment.
This technique is currently under developmentsince it would allow the full integration of computer systems into scientific research or their transmission over long distances and in real time, taking advantage of new technologies inspired by the Internet.
This also means that a step towards the automation of certain scientific analysis processes which could dispense with constant human intervention, such as histological examinations or blood samples.
Importance of the microscope for medicine
The birth of microscopy and the use of this tool in the various life sciences promoted a scientific revolution that was already being hinted at in theoretical terms.
Verification of life forms smaller than visible He completely abolished magical or religious theories about illnessand opened a scientific window for the verifiable study of the different infectious agents (viruses, bacteria, protozoa) and the body’s own chemistry (blood tests).
Microscope Care
A microscope must be used with some care so as not to damage its delicate operating system, how to carry it with both hands, since a fall is fatal; do not move it while using; do not touch the lenses or the eyepiece, as they get dirty easily; or avoid for the same reasons that the end of the objective touches the substance observed when approaching it to focus.