How to use a compound microscope
The compound microscope is a tool that allows you to see very small objects, such as cells and biological tissues, by using two or more lenses. This instrument is widely used in biology, medicine, chemistry, and other scientific disciplines.
The compound microscope consists of several parts, including:
- Eyepieces: the lenses that are looked through with the eyes and magnify the image;
- Objective lenses: the lenses near the object being observed that magnify the image;
- Stage: where the object being observed is placed;
- Light source: to illuminate the object being observed.
To properly use the compound microscope, it is important to know all of these parts and how they work together. Additionally, it is necessary to know how to prepare a sample for viewing under the microscope.
In general, the compound microscope can be used to:
- Observe cells and biological tissues;
- Analyze inorganic materials;
- Examine water or soil samples.
But its use is not limited to just these fields.
Sample preparation
Before being able to observe a sample under the compound microscope, it must be prepared properly. The preparation of the sample depends on the type of material being analyzed.
Dry samples
Dry samples, such as dried leaves or plant tissues, can be directly observed under the microscope without any further preparation. However, if a more detailed view of the sample's structure is desired, dry mounting can be used. To do this:
- Place the sample on the microscope slide;
- Cover the sample with a transparent cover slip;
- Ensure there are no air bubbles between the sample and cover slip.
Wet samples
Wet samples, such as living cells or fresh tissues, require more careful preparation to avoid distortion of cell shape and size during observation under the microscope. There are several methods for preparing wet samples:
Temporary mounting
Temporary mounting is a quick and inexpensive method for observing wet samples under the microscope. To perform this technique:
- Take a clean, dry microscope slide;
- Place a drop of saline solution on the slide;
- Position the sample on top of the saline solution drop;
- Cover the sample with a transparent cover slip, being careful not to trap air bubbles between the sample and cover slip.
Sample staining
Sample staining is a method used to highlight specific parts of the cell. There are numerous types of stains, each of which binds to specific components of cells. To perform this technique:
- Prepare a staining solution;
- Put a drop of solution on the sample;
- Let the dye act for a few minutes;
- Gently rinse the sample with water to remove excess dye;
- Mount the sample using dry mounting.
- Remember to clean the microscope after use and store it safely in its case.
- Practice observing different types of samples under the microscope to improve your skills.
- Clean lenses only with specific products for optics
- Use a soft cloth to clean the body of the microscope
- Regularly check bolts and screws
- Lubricate moving parts with specific oils
- Avoid sources of excessive heat or high humidity
With proper sample preparation, it will be possible to obtain sharp and detailed images under the compound microscope.
Microscope adjustment
To obtain clear and sharp images with your compound microscope, it is necessary to make a correct adjustment. Here are the steps to follow:
1. Illumination
Turn on the light and place the sample on the microscope stage. Adjust the brightness until you get uniform illumination throughout the visual field.
2. Coarse focus
By turning the coarse focus knob, move the objective lens down until it is a few millimeters from the sample. Make sure that the tip of the objective lens does not touch the sample.
3. Fine focus
Turn the fine focus knob to focus the image. This knob allows you to adjust the distance between the objective lens and the sample very precisely, in order to obtain a sharp image.
4. Diopter adjustment
Position the eyepiece in the center of the visual field. Close your left eye and adjust the diopter of the right eyepiece by turning its ring until the image is sharp. Repeat this operation for the left eyepiece.
By following these simple steps, you will be able to correctly adjust your compound microscope and obtain sharp and detailed images of your sample.
Observation under the microscope
To observe a sample under the microscope, it is important to follow some fundamental steps:
1. Sample preparation
First of all, the sample must be prepared appropriately. This means that it must be thinly sliced and mounted on a slide with a drop of mounting fluid. The mounting fluid helps keep the sample moist and prevents its evaporation during observation under the microscope.
2. Focus adjustment
After placing the slide on the microscope stage, adjust the focus using the two eyepieces and the coarse focus screw. Start with coarse focus and then move on to fine focus to obtain a sharp image of the sample.
3. Choosing the objective lens
Choose the right objective lens based on the size of the sample and its structure. More powerful lenses are used to observe smaller details, while less powerful ones are used to see larger structures.
4. Adequate illumination
Illumination is essential for good observation under the microscope. Adjust brightness and angle of illumination to obtain a sharp image of the sample.
5. Observation and recording of images
Observe the sample through the eyepieces and slowly move it to see all parts of the sample. If necessary, adjust the focus again or change the lens. Record images using a digital camera or smartphone connected to the microscope.
Cleaning and maintenance of the microscope
Cleaning and maintenance of the microscope are essential to ensure a clear view of observed objects and to prolong the useful life of the instrument. Here are some useful tips:
Cleaning the lenses
The lenses of the microscope must be cleaned with extreme care to avoid damaging or scratching them. Before cleaning, make sure there are no particles of dust or dirt on the lenses. Otherwise, gently remove them with a blower or soft brush.
To clean the lenses, use only specific products for optics, such as a microfiber cloth or swabs soaked in isopropyl alcohol. Avoid using toilet paper or other rough fabrics that could scratch the lenses.
Cleaning the body of the microscope
The body of the microscope should also be cleaned regularly to prevent accumulation of dust and dirt that could compromise its functioning. Use a slightly damp soft cloth to remove dirt from the outer surface of the microscope.
In case of persistent stains, it is possible to use a mild cleaning solution diluted in water. Avoid using too aggressive or abrasive products that could damage the surface of the microscope.
General maintenance
To prolong the useful life of the microscope, it is important to carry out some general maintenance operations. For example, regularly check bolts and screws to ensure they are securely fastened and lubricate moving parts with specific oils for delicate mechanisms.
In addition, avoid exposing the microscope to sources of excessive heat or high humidity, as this could compromise its functioning.
By following these simple tips, it will be possible to keep your microscope in perfect condition for years to come and always enjoy sharp and detailed images of observed objects.
Conclusions
The compound microscope is a very useful instrument for studying and observing objects at the microscopic level. Knowing its parts and how it works is essential to be able to use it properly. In addition, regular cleaning and maintenance of the microscope are essential to ensure optimal functioning over time.
By following the tips described in this article, it will be possible to use your microscope with greater safety and effectiveness, obtaining sharp and detailed images of the observed objects.
Michael Anderson - Software Engineer
My name is Michael Anderson, and I work as a computer engineer in Midland, Texas.
My passion is sharing my knowledge in various areas, and my purpose is to make education accessible to everyone. I believe it is essential to explain complex concepts in a simple and interesting way.
With GlobalHowTo, I aim to motivate and enrich the minds of those who want to learn.
