Disadvantages of Light Microscope

With the advancement in science and technology, the latest laboratory equipment has been introduced to help scientists and researchers with their work. Microscopes are one such lab equipment that allows the observer to examine tiny specimens and microorganisms. There are different types of microscopes with different magnifications and resolutions. Two of the most popular types are light microscopes and electron microscopes. Here, we will discuss the light microscope and its advantages and disadvantages.

What is a Light Microscope?

A light microscope, also known as an optical microscope, uses light at wavelengths of approximately 400 to 700 nm to illuminate and view objects. The resolution power of this type of microscope is 0.2 µm with a magnification range of 40x to 1000x. Light microscopes use glass lenses to form the image by absorbing light. This microscope is used to observe and view a variety of specimens, including fixed or unfixed, stained or unstained, and living or dead. The specimen under observation can be 5 micrometers or thicker. It is stained with dye, mounted on a glass slide, and observed under the light microscope.

Parts of a Light Microscope

Here is a list of all the parts of a microscope:

• Objective Lenses
• Eyepiece
• Ocular Lenses
• Aperture
• Nosepiece
• Rack Stop
• Light Source
• Head
• Stage
• Adjustment Knobs
• Arm
• Diaphragm
• Stage Clips
• Illumination
• Brightness Adjustment
• Microscope Arm
• Condenser
• Illuminator
• Base
• Iris Diaphragm

Disadvantages of Light Microscope

Any equipment or tool has its pros and cons. A light microscope has several advantages, but it is essential to consider its disadvantages to ensure whether this is the right tool for your research work. Let’s discuss them below:

Low Resolution

Light microscopes offer comparatively lower resolution than electron microscopes. It only allows a clear image when the specimen is at a lateral distance of less than half the wavelength of the light. Adding additional lenses to the light microscope does not improve the resolution. 

Inability to Form a 3D Image

Light microscopes cannot render an image’s 3D structure. It fails to provide in-depth information on three-dimensional structures. Scanning tunneling microscopes and scanning electron microscopes are used to study 3D structures. 

Low Magnification Power

Light microscopes have a relatively low magnification power of as low as 40x; an additional 10x ocular lens reaches a maximum of 100x. This magnification power is much less than that of a scanning electron microscope with a magnification power of up to 10,000,000x. 

Cannot Operate in Darkness

As light microscopes use a light source to illuminate the specimen under observation, they cannot operate in darkness. However, an artificial light source such as a built-in illuminator might be used to solve this problem. 

Requires Staining

Sometimes, locating smaller structures with a light microscope is difficult. Specimens are often stained to improve their visibility under a light microscope.

Advantages of Light Microscope

• Easy to Operate: One of the most significant advantages of light microscopes is that they are easy to operate. Their simple setup makes them accessible to anyone with minimal training and knowledge.
• Inexpensive: Light microscopes are cheaper than other types of microscopes, which makes them a good option for schools, colleges, and research labs with a minimum budget. Their maintenance cost is also lower.
• Ability to View Living Things: Light microscopes can view living specimens. This feature is limited to light microscopes only, as the beams of electron microscopes can kill living things.
• Unaffected by Electromagnetic Fields: One of the perks of this type of microscope is that it is unaffected by the changes in the environment, such as changes in the electromagnetic fields. Other microscopes are affected by the outside environment and adapt to the changes in the environment, and results might be affected.

Conclusion

Microscopes are an essential laboratory equipment. The light microscope is one of the earliest microscopes with a magnification power of 1000x and a resolution power of 0.2 µm. This type of microscope uses a light source to illuminate and form the image of the specimen under observation. There are six light microscope types: dark-field, phase-contrast, fluorescent, differential interference contrast microscope, confocal microscope, and polarized microscope. Light microscopes are easy to use and are cheaper but unsuitable if you require higher resolution and magnification power. They cannot operate in darkness and cannot provide a detailed image of a three-dimensional structure.