8 Things You Need to Know About Using a Light Microscope in Biology Class

Using a light microscope is a great way to learn about the world around you. When students first begin learning about biology, they usually focus on using microscopes to examine individual cells. However, a light microscope is also an excellent way to understand biological processes such as photosynthesis and cellular respiration.

A light microscope is a device that magnifies objects many times, up to 10,000x. A cheap and simple alternative to these costly microscopes is the essential handheld microscopes that you can buy for under $10. These magnifications range from 4x to 400x and can be used to inspect various materials such as food, insects, fossils, and minerals. 

In this article, we will discuss how to use a light microscope and provide step-by-step instructions on how to start with basic microscopy in just 10 minutes. We will teach you what equipment you need and how to use it.

What are the basic parts of the light microscope?

The essential parts of a light microscope include the following items: a focuser, oculars with condenser and illuminator, objectives or lenses, specimen stage, an imaging device (camera), and an illumination system.

1. The focuser focuses on the image at one point while the camera takes a visible picture through the lenses attached.

2. Oculars are then attached to each side of the camera lens. In addition, a condenser is placed in front of the microscope, and an illuminator is used for illuminating the specimen stage. A Condenser for a light microscope is an optical device that collects and converges the light falling on it into one point.

It can be called “Ocular” because all condensers have different roles in microscopy:- focal plane condenser, Fourier transform interferometer (ST-IM), relay grating (RD), and fringe finder. These objectives are specific parts of any standard light microscope.

3. The objectives may also be used as at least one objective lens that can fit into your camera’s attachment.

4. A close-up observation set (the distance from a microscope) contrasts with a far backdrop when imaging through lenses on both ends. usually, two or more small glass spreads so that none of its features appear out too much, but when you take a picture with your microscope, the specimen stage appears in plain sight.

5. It also requires software to decode what is observed from an image captured by that camera. At first, you need to decide which features of interest are seen and then try to filter out those you don’t have time for or even just flat-out ignore when there is too little detail or complexity revealed

6. Light microscopes use illumination systems to create the image. Usually, a light source, sometimes called an illuminator, emits radiation directly onto an object through the system. This can be any light source, including fluorescent lights, incandescent lights, and lasers.

7. An arc lamp is another common light source component used with microscopes. Arc lamps are provided by vacuum tubes having a non-transparent cathode and a metal anode (screen).

8. Lasers can also be attached if desired, but this feature needs special alignment-related skills. Once you’ve aligned everything, tape the laser beam onto then slide it into place using hot glue to keep its position steady and ensure that any stray light does not hit your specimen.

The detector is an electronic instrument that registers the incident radiation reaching its surface and converts it into a binary code for further processing, analysis, or display purposes (e.g., by a microscope control computer).

Uses of Light Microscope Parts:

1. When you need to collect light rays reflected off the specimen, it is essential to use an objective lens.

2. You can use stage clips to secure your specimen, stopping the sample from moving during the examination.

3. When preparing a microscope slide, all specimen parts must be visible equally, and it is also essential to ensure that the condenser is used correctly.

4. When the stage is moved, the distance between the object and the objective will be adjusted in a soft focus.

5. To avoid the specimen getting too much light, the manufacturer used a luminous-field

Before learning to use a light microscope, you should know how to prepare a specimen. 

To prepare your sample, follow the steps below

1. put a few drops of fluid in the middle of the slide; you can utilize tweezers.

2. A coverslip is needed to protect the sample.

3. Ensure the slip is in contact with the fluid drops’ perimeter.

4. To avoid air bubbles, protect the sample completely.

5. If fluid remains outside the coverslip, use a paper towel to separate the excess fluid.

How to use a light microscope: Follow these easy steps below 

1. Make sure that the stage is as low as possible. Start at the lowest power level and gradually increase as you progress.

2. Your specimen should be placed right under the objective lenses, so position your slide like this. Do not neglect to protect the sample with a glass lid designed to cover both your model and the objective lenses.

3. The stage clips can then be attached to lock the position of the slide.

4. Adjust the mirror’s position so that most of the light is reflected onto your slide. If your microscope includes an illuminator, spin the light source to reproduce the maximum amount of light on the specimen. Make sure that the light is directly focused on the center of your sample at all times.

5. The color of light will vary depending on the light’s source, including the wavelength. The wavelength is longer, the light is redder or whiter, and vice versa.

If a sample carries resorcinol, ultraviolet light can be reflected at them, creating staining and discoloration on the sample. When conducting research, a lot of times, it is difficult to get a colored model.

6. Move the rough adjustment knob to adjust the image. Slowly lift the stage to get a stronger focus. The focus knob and the coverslip should be placed in close contact. 

7. Move the small adjustment knob for a focused image.

8. Before changing to medium power, apply the lowest power view on the specimen. Be careful while rotating the nosepiece to ensure that it does not break.

9. Changing the objective lens to medium and focusing via fine adjustment is the same option. If you are unable to view your specimen, repeat steps 1 through 5 on a repeat basis.

10. You can increase the capacity of the specimen’s image is focused on medium power.

 11. Thoroughly rotate the objective lens node until the specimen’s highest point is visible after examining or studying the specimen. Turning the nosepiece to the lowest power of the lens, remove the slide carefully, and protect your microscope with a cover. 

After understanding how to operate a microscope, it is time to clean and secure it for personal use. Here are a few things you should remember to keep the microscope as safe and clean as possible.

Make sure that you are holding your microscope with both hands. For support, lift the microscope’s arm with one hand and place the other hand to hold the microscope’s bottom.

Always cover the microscope with a cloth when it is not being used.

You can use Laser paper to clean the lens glass and avoid affecting the lens.

4 Things that are usually done wrong when using a light microscope:

1. You don’t adjust your lighting for different refractions (magnification) of samples in the case of complex specimens or if some elements on the material may have curved shapes, which will affect observation under certain conditions like condensation-coating, etc.

2. Be careful when adjusting the adjustable foot of a stage so that it doesn’t apply more pressure to harmful materials like paper and other non-supporting objects.

3. Don’t leave samples sit at room temperature; healthy specimens should always be observed in warm conditions, which would help maintain specimen clarity as well as tissue elasticity for examination better results or longer observation time under certain circumstances; however, do not keep them at extreme temperatures or immature specimens can be distorted.

4. Always use a typing liquid with most filtering materials to maintain the quality of samples (e.g., water or saline, ethanol), while using some critical or aggressive chemicals (such as acid) could potentially damage their structural integrity even if appropriately handled a light microscope often has glass slides on which various types specimen are placed for observation at certain times within an examination process.

Hence, it is essential that you check those glass slides for any contamination of the type or “changing color” that may be caused by non-organic materials, such as solvents (e.g., oils), oil pastes and their residues, etc.

FAQs

What are the advantages of light microscopes?

Light microscopes are used to examine tiny objects in the form of a magnified image. They are used primarily for biological specimens, including cells and tissues, but can also be used on materials like crystals or minerals.

Advantages of light microscopes:

They can be cheaper than other microscopes because they don’t require a high-voltage source or bulky equipment. 

Light microscopes have a lower resolution than other types of microscopes, meaning that more time is needed to produce an image, and there is less detail. 

Light microscopes have better portability than most other microscopes because they don’t need a power source or bulky equipment.

Every time you need to work the microscopes, a Magnifying Lamp and control do not have to be taken out.

They can be mounted on different machines, including cameras, scanners, microtomes, and electron-optical traps. 

Their magnification range varies from low (2x) to high (200x).

They are easy to use and have less noise than other microscopes.

What are the disadvantages of light microscopes?

Light microscopes are the most commonly used type of microscope in research labs and classrooms.

However, there are some disadvantages as well

Main disadvantages of light microscopes:

Objects can only be seen with a magnification of about 200, microscope slides are fragile and do not last long when placed under the microscope. Although I magnify by 500x, the sample is still just an extended hand for your eyes, you may want to consider binoculars (e.g., magic eye viewer) so that you can also see what’s in front of or behind.

The cases do not allow air circulation, and cloning gel or other conservant media has to be used. It takes a week before it reaches optimal condition when bacteria and fungi might have already destroyed the sample.

Light transmission can be uneven, meaning that certain parts of a specimen may be seen well and other factors not so well.

The most obvious problem is their light sensitivity: they (the microscope slides) are delicate and easily destroyed by strobe flashes which act as additional light sources once installed in your cock-pit. The best free book evaluating microscopic tissue samples for damage from laser radiation.

One person can go through the same scope at any given time, so it will force you to have to wait in order with somebody else if the room is not large enough.

These microscopes are more technical, and it comes down to the projector. Because they use light instead of visible light, they can project images on anything in the direct path of their lens.

You cannot use them to view the biological matter, as they require a live specimen. Light microscopes require that the sample be placed in aluminum foil which can lead to contamination issues if not done carefully and correctly.

Light microscopes are limited in the magnification range, especially when compared to scanning electron microscopes. Light microscopes require lenses because they do not focus light.

What is the difference between a light microscope and an electron microscope?

A light microscope is an optical microscope that uses an objective lens or 10X objective to magnify distant objects and illuminate them sufficiently for an observer to see them. This type of microscope must use illumination by transmitted or reflected light, not direct electromagnetic radiation. Light microscopes are used in industrial and scientific applications such as cell biology, biomaterials, histology, microbiology, and medical pathology.

An electron microscope uses a beam of electrons to illuminate specimens and images. Because the beam passes through many lenses (see below), a high-resolution image may be produced provided enough incident photons make it past lens elements, which usually is not an acceptable probability for objects at microscopic distances.

Also, because electron microscopes cannot view wide-angle fields of view or correct for chromatic aberrations in illumination sources like low-intensity incandescent light bulbs, whose wavelengths vary much during their useful lifetime, the resolution of an electron microscope is limited by what lenses can be included in the specimen-mounting apparatus.

Main difference between a light microscope and an electron microscope

Resolving power 

An electron microscope has a resolving power of approximately 100,000 times that of a light microscope. This means that an electron microscope can see objects at a much smaller scale than a light microscope can.

Specimen preparation

Preparing a specimen with a light microscope takes approximately 10 minutes while preparing a sample with an electron microscope takes about 30 minutes.

Objective lens

A light microscope uses an objective lens with a wide aperture to collect light and magnify the image.

An electron microscope uses an objective lens with a narrow aperture that focuses electrons on the specimen, thereby providing high-resolution imaging of some objects that are too small for standard optical microscopes.

Maximum Magnification

Using the microscope helped you to see cells and bacteria better. Nowadays, scientists use several different types of microscopes to study other things. The electron microscope looks at tiny samples or pictures that cannot be seen with a light microscope.

Is a light microscope illuminated only with sunlight?

No, a light microscope is illuminated with a halogen lamp. Halogen lamps provide excellent illumination for both fluorescent and darkfield microscopy.

Halogen lamps are widely used in optical instrumentation due to their low heat output, compact size, and wide range of spectral results.