Home » 7 Different Types of Microscopes and Their Uses

7 Different Types of Microscopes and Their Uses

Microscopes are essential tools in the scientific community, allowing researchers to study and analyze samples at a microscopic level. There are several different types of microscopes, each with its own unique features and capabilities. In this post, we will introduce you to 7 different types of microscopes and their uses.

A microscope is a form of optical instrument typically seen in a laboratory setting, where it is used to examine tiny objects that the human eye simply cannot see. There is a wide variety of microscopes available, and we’re employing each one for a certain task. One can classify microscopes according on their function and use.

Types of microscopes

Figure 1: 7 Different Types of Microscopes

Different Types of Microscopes

There are mainly 7 common types of microscopes as follows: 

  1. Compound microscopes
  2. The Stereomicroscopes
  3. The Confocal microscopes
  4. The Electron microscopes
  5. Polarizing microscopes
  6. Phase-contrast microscope
  7. Fluorescence microscopes

1. Compound Microscopes

Compound microscopes, as its name implies, feature multiple lenses. The objective lens and the ocular lens are the two optical components of a compound microscope, which is a system of combined lenses.

compound light microscope labeled

Figure 2: Compound Light Microscope Labeled

Principle

Compound microscopes have a number of lenses that work together to improve both the ability to magnify and the ability to see features. Typically, the specimen or item to be examined is put on a transparent glass slide and positioned between the condenser lens and objective lens on the specimen stage.

A condenser lens brings a beam of visible light from the base to the specimen. The objective lens picks up the light that the specimen lets through and makes a magnified image of the specimen inside the body tube. This image is called the primary image. The ocular lens, also called the eyepiece, again makes this image bigger.

When higher magnification is needed, the nose piece is turned after focusing at low power to bring the higher power objective (usually 45X) into line with the part of the slide that is illuminated. It sometimes needed a very high magnification (e.g. for observing bacterial cell). In this situation, a 100X oil immersion objective lens is used.

Applications

Compound microscopes are utilised extensively in numerous disciplines, including biology, medicine, and materials research. Observing and analysing cells, analysing samples, examining tissues and tissue samples, doing quality control, and educating are common applications of the compound microscope.

2. Stereomicroscopes

A stereo microscope is a type of optical microscope that lets you see an object in three dimensions. It is also called a dissecting microscope and a stereo zoom microscope, among other names.

Stereomicroscope Images

Figure 3: Labeled Dissecting microscope (Stereo or Stereomicroscope Images)

Principle

Reflected light from an object is used by a stereo and a dissecting microscope. It has a low power, which makes it perfect for magnifying things that are hard to see. It is useful for looking at solid or thick samples because it uses light that the sample naturally reflects. The magnification of a stereo microscope is between 10x and 50x.

The magnification and the working distance can be changed by attaching additional supplementary or auxiliary lenses. You’ll need a lens with a magnification factor of less than 1x (e.g., 0.3x, 0.5x, or 0.7x) if you want to increase your working distance. A microscope’s overall magnification can be increased to 300x or more with the help of an ocular lens or eyepiece.

Applications

A dissecting microscope allows for live, hands-on specimen observation and handling. A dissecting microscope, as compared to a standard compound microscope, has a larger working distance, making it possible to perform microsurgery. These microscopes are used for a wide variety of tasks in the biological and medical sciences.

Magnification provided by a stereo microscope makes it possible to classify and observe item edges and corners in three dimensions, facilitating a more complete analysis. Anyone interested in viewing or working with materials on a microscopic scale can benefit from a stereo microscope. This includes technicians fixing circuit boards, palaeontologists cleaning and examining fossils, mud loggers, specialists analysing fabrics, and more.

Depending on the settings, stereo microscopes can be used for almost anything. There is a wide selection of stands and mounts available to accommodate your display needs. These include boom stands, articulating or flex arms, plain stands, track stands, table mounts, and more. As an added bonus, specimens can be seen with more clarity and brightness with the help of microscope illuminators.

3. Confocal Microscopes

Confocal microscopy is often used to find out more about the structure of certain things inside a cell. Immunofluorescence, for example, can be used to label specific parts of living or fixed cells or tissue sections so that they can be seen in high resolution.

Confocal Microscope Diagram

Figure 4: Confocal Microscope Diagram

Principle

The light from the laser is directed through a series of lenses and mirrors, which focus the beam onto a tiny spot on the sample. A detector, such as a photomultiplier tube or a charge-coupled device (CCD), is used to measure the light that is scattered or emitted by the sample.

One of the key features of confocal microscopes is that they use a pinhole or a spatial filter to eliminate out-of-focus light from the image. This helps to improve the resolution and contrast of the image, and allows for the visualization of structures within the sample that are separated by small distances.

Applications

Confocal microscopes are used in a variety of scientific and medical applications, including: Biological imaging, Material science, Nanotechnology, Medical research, and Industrial inspection.

4. Electron microscopes

Electron microscopes are specialised scientific tools that use a beam of electrons to make images of samples with a high level of detail. They work by sending a beam of electrons through a series of lenses and holes, which focuses the beam on a tiny spot on the sample. Depending on what the sample is made of, the electrons interact with it and are either scattered or taken in. There are several types of electron microscopes, including transmission electron microscopes (TEMs), scanning electron microscopes (SEMs).

i) TEM Microscope

Principle

The way the Transmission Electron Microscope (TEM) works is the same as the way the light microscope works. The main difference is that light microscopes use light rays to focus and make an image, while the TEM uses a beam of electrons to focus on the specimen and make an image. Light has a long wavelength, while electrons have a shorter wavelength. In a light microscope, when the resolution power goes up, the wavelength of the light goes down. 

In a TEM, on the other hand, when the electron shines on the specimen, the resolution power goes up, which makes the wavelength of the electron transmission longer. The wavelength of an electron is about 0.005nm, which is 100,000 times shorter than the wavelength of light. Because of this, TEM has about 1000 times better resolution than a light microscope.

transmission electron microscope images

Figure 5: Transmission Electron Microscope Images

Applications

TEM is utilised in biology, microbiology, nanotechnology, and forensics. These include: To research bacterial, viral, and fungal cell structures, Flagella and plasmids of bacteria, View microbial cell organelle forms and sizes, Comparing plant and animal cells., Nanotechnology uses it to research nanoparticles., It detects fractures and damaged microparticles, enabling healing mechanisms.

ii) SEM Microscope

Principle

Scanning electron microscopes (SEMs) use a concentrated stream of high-energy electrons to produce different signals on the surface of solid specimens. Information about the sample, such as its exterior appearance (texture), chemical composition, and crystalline structure and orientation, can be collected from the signals resulting from electron-sample interactions. In a scanning mode, standard SEM techniques can produce images with a width of anywhere from around 1 cm to 5 microns (magnification ranging from 20X to approximately 30,000X, spatial resolution of 50 to 100 nm).

scanning electron microscope images

Figure 6: Scanning Electron Microscope Images

Applications

It is used in many different fields, such as industry, nanoscience, biomedical research, and microbiology.  Used in energy-Dispersive X-ray spectroscopy to do chemical analysis on the spot. Used to analyse very small parts of cosmetics.  Used to look at the structures of microorganisms filaments.  Used to learn about the topography of things that are important to industries.

5. Polarizing Microscopes

Polarizing microscopes are specialized optical instruments that use polarized light to study the structure and properties of samples. They work by illuminating the sample with a beam of polarized light, which is light that oscillates in a specific direction.

polarized light microscopy images

Figure 7: Polarized Light Microscopy Images

Principle

A polarizer stands between the light source and the sample in a polarised light microscope. So, before the polarised light source hits the sample, it is changed into plane-polarized light. When this polarised light hits a double-refracting object, it makes two parts of a wave that are perpendicular to each other. These two types of light waves are called “ordinary” and “extraordinary.” Different phases of the waves pass through the specimen. An analyzer then combines them using constructive and destructive interference. This results in the creation of a high-contrast image.

Applications

Polarizing microscopes are commonly used in a variety of fields, including mineralogy, petrology, materials science, and biology. Some specific applications of polarizing microscopes include: Identifying minerals, Analyzing rock formations, Examining materials, Analyzing biological samples, and Quality control.

6. Phase-contrast Microscope

A phase-contrast microscope is a type of microscope that lets you see small details in things that are clear or almost clear, like cells, tissues, and microorganisms. It is especially useful for studying living cells and tissues because the person using it can see them in their natural state without having to stain them or do other things to get them ready.

phase contrast microscope image

Figure 8: Phase Contrast Microscope Image

Principle

The phase-contrast microscope is based on the idea that light waves travelling through a transparent or semitransparent material will be slightly phase-shifted. This phase shift is detectable and can be utilised to generate a picture of the specimen.

A phase-contrast microscope utilises a phase-contrast objective lens to detect the phase change of light waves flowing through a specimen. A small annular stop within the phase-contrast objective blocks a portion of the light passing through the objective. Unblocked light goes through the specimen and is caught by the eyepiece or camera. The light that is stopped by the annular stop is recombined with the light that passes through the specimen, and the interference pattern that results is used to form an image of the specimen.

Applications

Phase-contrast microscopy is a widely used technique in the fields of biology and medicine for studying the structure and function of cells, tissues, and microorganisms. Some specific applications of phase-contrast microscopy include: Observing living cells, Analyzing tissues, Examining microorganisms, Investigating cell division, Studying cell motility, Analyzing cell cultures.

7. Fluorescence Microscopes

A fluorescence microscope is a type of microscope that uses fluorescent dyes or proteins to see specific structures or molecules in a sample. Fluorescence microscopy is a powerful tool that lets scientists study the structure and function of cells and tissues at the molecular level.

fluorescence microscope image

Figure 9: Fluorescence Microscope Image

Principle

A fluorescence microscope employs a light source, such as a mercury lamp or laser, to illuminate a specimen with a specific wavelength of light. Additionally, the sample is treated with a fluorescent dye or protein that is particular to the examined structure or molecule. When the dye or protein absorbs light, it becomes stimulated and emits longer-wavelength light; this phenomenon is known as fluorescence.

A specific detector, such as a camera or eyepiece, collects the emitted light and uses it to build an image of the sample. To visualize the fluorescence, specific filters are required to block incident light and allow only the emitted fluorescence to pass through.

Applications

Fluorescence microscopy is a powerful tool that is used in a wide range of applications, including biology, medicine, materials science, and chemistry. Some specific applications of fluorescence microscopy include: Studying cells and tissues, Analyzing microorganisms, Investigating cell division, Studying protein localization, Analyzing cell signaling pathways, Examining material properties.

FAQ

FAQs on Different Types of Microscopes

Multiple types of microscopes exist for studying viruses. The electron microscope is the most popular choice for this application.

A light microscope, often known as a compound microscope, is the type of microscope most commonly used in class rooms.

The light source can be a bulb, a fluorescent lamp, or an LED, and it is usually placed below the stage where the specimen is mounted.

Transmission electron microscopes (TEM) can’t take pictures of living things because they use a beam of electrons to make an image, which can hurt or kill the specimen.

There are mainly 7 common types of microscopes as follows: 

  1. Compound microscopes
  2. The Stereomicroscopes
  3. The Confocal microscopes
  4. The Electron microscopes
  5. Polarizing microscopes
  6. Phase-contrast microscope
  7. Fluorescence microscopes