God created living things on this earth is very diverse. Starting from living things that are very small and cannot be seen directly with the naked eye, as well as large living things like us, humans. Without us knowing it in our bodies there are creatures that are very small in size that we cannot see, namely cells.
Cells are very small and can only be seen using a special tool, namely a microscope. Some types of living things that cannot be seen directly by the eye and a microscope is needed to be able to see them include: microscopic objects, bacteria, plant cells, blood cells, plant fibers, cross-sections of leaf surfaces, and others. So living things that were originally invisible can be seen with the help of an instrument, namely a microscope.
The microscopes in schools are usually monocular microscopes and ordinary light microscopes, namely microscopes that are used only with one eye and usually use sunlight or natural light to be able to see the object. In addition, the object must also be smaller and thinner, so that light can penetrate.
There are also school laboratories that use other types of light microscopes, such as a stereo microscope (two oculars) so that it can be observed by two eyes and an ultraviolet microscope which is used with the help of ultraviolet light. But there are also some microscopes that use both a photographic microscope and a phase microscope.
The characteristics of a light microscope include:
1. A light microscope uses light as a source of light and a lens is needed to reflect the light.
2. Preparations must be translucent so that objects can be seen clearly, objects can be observed in a state of life or death.
3. The resulting image can be enlarged up to 100x, 400x and 1000x.
Parts of a Light Microscope
Optical parts include:
a. Two mirrors, namely a plane mirror and a concave mirror, are used to find, collect and reflect light on the object being observed.
b. The diaphragm serves to regulate the amount of light that the mirror will reflect into the eye.
c. The ocular lens is located at the top of the tube which serves to enlarge and clarify the image of the object.
d. The objective lens is located on the revolver which serves to enlarge the image of the object.
The mechanical parts of the light microscope include:
a. Microscope legs function to support the microscope.
b. The inclination joint serves as a link between the legs and the arm of the microscope.
c. The condenser has the function of focusing light on the object to be observed.
d. The condenser controller has the function of adjusting the position of the condenser to the object.
e. The microscope arm serves to hold the microscope so it doesn't fall off during the observation process.
f. The driving hinge whose function is to connect the arm and leg of the microscope.
g. The preparation table whose function is to put the preparations later to be observed.
h. The clamp of this preparation serves so that the object being observed does not shift or change position.
i. The tube is used to connect the objective and eyepiece lenses.
j. Revolver serves to place the objective lens.
k. Coarse turning screw (macrometer) which functions to move the tube quickly from top to bottom.
l. Soft turning screw (micrometer) which functions to move the tube slowly from the top to the bottom.
The steps for using a light microscope are to hold the arm of the microscope with the right hand and the foot of the microscope with the left hand, then first adjust the proper irradiation at the position of the lens and microscope mirror, then adjust the focus of the microscope with low magnification, followed by adjusting the focus of the microscope, then adjust the microscope with the position stored on the table then observations can be made.
Along with the times, especially in this era of globalization, there have been many significant changes in the world of technology, as well as the use of a microscope as an indispensable tool for learning in schools.
As discussed earlier, now we know that microscopes are more sophisticated in line with the increasing needs of research that will be carried out.
This electron microscope was invented around 1960 by a western scientist. The advantage of this electron microscope is that it has a resolution power that is much better than a light microscope and can magnify objects 2 million times and even up to 45 million times using electrostatics and electromagnetics.
Both of these tools function to regulate and control the lighting of objects and their magnification. Electron microscopes require more energy and shorter electromagnetic radiation than light microscopes.
The use of this electron microscope serves to facilitate research and observations made by scientists. In Indonesia, the number of electron microscopes is still very limited, namely only in certain universities. This is because the price is quite expensive compared to light microscopes.
The characteristics of the electron microscope include:
1. The electron microscope uses electrons instead of light and also a magnetic field to replace the lens. The image is displayed on the monitor screen.
2. This electron microscope is usually used in observing cell parts such as organelles, membranes, or large molecules such as DNA.
3. The object to be studied must be very thin and located in a vacuum so that electrons can penetrate.
4. The image obtained can be enlarged up to two million times or more.
There are two types of electron microscopes, namely scanning and transmission electron microscopes. Scanning Electron Microscope (SEM: Scanning electron microscope) functions to observe in detail the cell surface.
The way the image is formed on a scanning microscope will be different from the image on an optical microscope. While the Transmission Electron Microscopy (Transmission Electron Microscopy) serves to observe the internal structure of the cell.
Actually, there are several weaknesses in this electron microscope because the object that can be observed must be as thin as possible. This is very confusing to scientists because not all objects can be made thin there are some objects that cannot be thinned.
However, along with the development of the world of technology, scientists are increasingly making developments to continue to create better and more advanced electron microscopes.
So now the electron microscope is not only able to observe dead preparations, but is also able to observe even living preparations using video equipment. Even in France there was a film company that made animated films of the life of small creatures so that the audience could see in detail the feathers of flies and other small animals.
To conduct better research and observation, it is necessary to have very mature preparations including: it is necessary to do fixation, which is to turn off the cells to be observed without changing the cell structure of the object, after that the dehydration stage is carried out on the object which serves to reduce the water content contained in the object. to be observed, thus facilitating the process of observing certain objects.