In this post we are going to break down the various characteristics, qualities and methodology of use, among other aspects of a microscope. From each of them it will be known what a microscope is, its definition, meaning and concept.
In general terms we can tell you that the microscope is an instrument that is used to observe and study very small objects. These objects are characterized by having a microscopic size.
The invention of the microscope dates from 1590, although there is a dispute about who was the creator between Galileo Galilei and Zacharias Jansen. Jansen is officially recognized as the creator. While Galileo was recognized as one of the first to use and improve the first model of the microscope.
In order to arrive at a good understanding of the meaning and concept of what a microscope is, it could be said that one needs to have knowledge. That is, keep in mind what some basic terms mean. Like the elements that make up a microscope. Let’s see.
Parts and components of a microscope
There are several types of microscopes, depending on the object that is decided to study and observe, the appropriate tool can be chosen. The following are the most common parts and components of a microscope.
- Platen adjustment: it is a screw that allows you to move the platen in different directions in a circular way. Not all microscopes have this feature, so it is only found when the stage has a rotating feature.
- Arm / column: this piece is the one that holds the tube and is coupled with the foot of the microscope. It normally has an arched or upright shape.
- Condenser: they are a set of lenses located under the stage, their main function is to capture and concentrate light rays on the object or observation sample.
- Diaphragm: it is a device that is located just above the light reflector and its function is to regulate the intensity of light.
- Light source: it is a kind of lamp that emits the necessary light for the observation of the samples. It is located on the foot of the microscope, it has a reflector that directs the light towards the stage.
- Objective: while the eyepiece is understood to be the lenses closest to the observer. The objective refers to the lenses closest to the sample, since through these the image can be increased. They are operated through the nosepiece and have features such as colored rings to identify their magnification capacity, and are also operated in a clockwise direction.
- Eyepiece: refers to the converging lens found on the inside of the microscope. Depending on the number of eyepieces, they can be monocular or binocular.
- Foot: as its name indicates, it is the base of the microscope.
- Tweezers: these are a part of the stage and their function is to hold the samples.
- Plate: is the element that is responsible for providing support to the slide. It has a hole through which light passes into the sample. It is also provided with two clamps.
- Revolver: this piece is the one that supports the multiple objectives and allows their rotation.
- Macro metric screw: as its name indicates, it is a screw used to focus and quickly move the lenses.
- Micrometric screw: unlike the previous one, this screw is used to focus and move the lenses slowly.
- Transformer.
- Tube: this element is the point of convergence between the eyepieces (at the top) and the nosepiece (at the bottom). It is cylindrical, hollow and black on the inside to ensure observation of the sample without light distractions.
Types of microscopes
- Stereo microscope or dissecting microscope
- Confocal microscope
- Fluorescence microscope
- Field ion microscope
- Reflected light microscope
- Optical microscope
- Compound microscopes
- Scanning probe microscopes
- Antimatter microscopes
- Dark field microscopes
- Phase contrast microscopes
- Scanning tunneling microscopes
- Atomic force microscopes
- Polarized light microscopes
- Digital microscopes
- Electron microscopes
- Scanning electron microscopes
- Transmission Electron Microscopes
- Reflected light and transmitted light stereo microscopes
- Monocular, binocular and trinocular microscopes
- Petrographic microscopes
- Simple microscopes
- Virtual microscopes
Main uses of a microscope
The microscope as a tool has a main task, which is to observe objects that are impossible to see with the naked eye. Such is the case of cells, spermatozoa, the DNA chain, among countless samples. It does this by producing large-scale images of extremely small samples. For this, it relies on the use of magnifying lenses, which are distributed between the eyepieces and the objectives.
How to use a microscope?
- Preparation: depending on what you want to observe in a certain sample, it is important to highlight specific areas in the object of study. The processes to prepare the samples are known as fixation and staining.
- Fixation: this technique is used when the sample needs to remain still, that is, without movement. To achieve this, dehydration methods are used, either by increasing the temperature or by applying special liquids.
- Staining: this method is based on improving the contrast in the image obtained from the microscope. This is accomplished through dyes and dyes that react to specific elements within a sample. In this way it is easier to observe a specific area.
Observation process, after preparing the sample, we proceed to:
- Placement: the sample is placed on the slide covered with another glass sheet.
- Calibration: after having the sample on the stage, the best position of the lenses must be sought to carry out the observation satisfactorily.
Other steps:
- Magnification is achieved by properly matching eyepieces and objectives.
- The focus is carried out through the coarse and micrometric screws.
- The light finally regulates the amount of light that is needed through the diaphragm.
Basic care for a microscope
Cleaning is a very important topic when talking about the good maintenance of a microscope. This should be a priority each time this instrument is used. It is believed that the greatest enemy is dust, because when it is not removed properly it can scratch the different glass lenses that make up a microscope. Likewise, it should be said that the other security measure is to keep the microscope covered, to avoid dust as much as possible.
Tips
Currently there are microscopes capable of producing high quality images, which do not necessarily use glass lenses or white light. As an example, mention can be made of the ultraviolet light model, in which the lens material is quartz and the light comes from mercury lamps.
Each of the types of microscopes mentioned above might serve better in specific analysis situations. For example, the phase contrast microscope is structured in a specific way. So that it is possible to observe cells without the need for them to be subjected to the staining process. This is because living organisms do not support dyes, since they destroy their cell structure to the point of death.
Following in that same order, it is advisable to investigate what type of microscope would be the most suitable to carry out certain studies. Ensuring a successful observation.