Top 10 Microscope Brand & Manufacturers

What is a Microscope?

A microscope is a scientific instrument designed to magnify small objects or details that are otherwise invisible or difficult to observe with the naked eye. It uses a combination of lenses or other optical components to produce a magnified image of the specimen. Microscopes play a crucial role in various fields such as biology, medicine, materials science, and geology, enabling researchers and scientists to study the structure and behavior of microscopic organisms, cells, and materials at a much finer scale.

History of the Microscope

• The origin of the microscope can be traced back to the late 16th century. Dutch spectacle - makers Zacharias Janssen and his father Hans are often credited with inventing the first compound microscope around 1590. Their early design consisted of multiple lenses in a tube, which could magnify objects up to a certain degree.
• Antonie van Leeuwenhoek, a Dutch tradesman and scientist in the 17th century, made significant contributions to the development of microscopes. He was a master at grinding and polishing lenses, creating simple microscopes with high - quality single lenses. His microscopes could achieve magnifications of up to 270x, allowing him to observe microorganisms like bacteria and protozoa for the first time, thus opening up a new era in microbiology.
• Throughout the 18th and 19th centuries, continuous improvements were made to the design and quality of microscopes. The development of achromatic lenses, which corrected chromatic aberration, was a major advancement. This improvement made the images clearer and more accurate, facilitating more detailed studies in various scientific disciplines.
• In the 20th century, the microscope evolved further with the advent of electron microscopes. The transmission electron microscope (TEM), developed in the 1930s, used a beam of electrons instead of light, enabling much higher magnifications and resolutions. This allowed scientists to study the internal structure of cells and molecules. Later, the scanning electron microscope (SEM) was developed, which provided detailed three - dimensional images of the surface of specimens.

Purpose of the Microscope

• Biological Research: In biology, microscopes are used to study the structure and function of cells, tissues, and microorganisms. They help in understanding biological processes such as cell division, metabolism, and the behavior of bacteria and viruses. Microscopes are also essential for taxonomy, where they are used to identify and classify different species based on their microscopic characteristics.
• Medical Diagnosis: In the medical field, microscopes are crucial for diagnosing diseases. Pathologists use microscopes to examine tissue samples, blood smears, and other biological specimens to detect the presence of abnormal cells, such as cancer cells. Microscopic examination can also help in identifying the causative agents of infectious diseases, like bacteria and parasites.
• Materials Science: Microscopes are used to study the microstructure of materials, including metals, ceramics, polymers, and composites. By observing the internal structure of materials at a microscopic level, scientists can understand their mechanical, electrical, and chemical properties. This knowledge is used to develop new materials with improved performance and to troubleshoot material - related problems in manufacturing processes.
• Geological Studies: Geologists use microscopes to study thin sections of rocks. By examining the minerals, textures, and structures within the rocks, they can determine the rock's origin, history, and the geological processes that have affected it. Microscopic analysis of rocks can also help in identifying potential sources of minerals and hydrocarbons.

Principle of the Microscope

• Optical Microscopes: These work based on the principles of light refraction. A light source, either natural or artificial, illuminates the specimen. The light passes through the specimen and then through a series of lenses. The objective lens, which is close to the specimen, magnifies the image of the specimen. The magnified image is then further magnified by the eyepiece lens, which the observer looks through. The total magnification of an optical microscope is the product of the magnification of the objective lens and the eyepiece lens. For example, if the objective lens has a magnification of 40x and the eyepiece has a magnification of 10x, the total magnification is 400x.
• Electron Microscopes: Electron microscopes use a beam of electrons instead of light. The electrons are emitted from an electron gun and accelerated through a high - voltage field. These electrons interact with the specimen, and the scattered or transmitted electrons are then focused by electromagnetic lenses to form an image. Transmission electron microscopes (TEM) transmit the electron beam through a very thin specimen, allowing the study of internal structures. Scanning electron microscopes (SEM) scan the electron beam across the surface of the specimen, and the secondary electrons emitted from the surface are detected to create a three - dimensional image of the surface.[!--empirenews.page--]

Features of the Microscope

• Magnification: Microscopes offer a wide range of magnifications. Optical microscopes typically have magnifications ranging from 40x to 1000x or more, depending on the combination of lenses. Electron microscopes can achieve much higher magnifications, with TEMs capable of magnifying up to several million times, and SEMs up to around 500,000x.
• Resolution: Resolution is the ability to distinguish between two closely spaced objects. A high - resolution microscope can clearly separate and show details of closely - located features. Optical microscopes are limited in resolution due to the wavelength of light, with a maximum resolution of around 0.2 micrometers. Electron microscopes have a much higher resolution, allowing them to resolve details down to the atomic level in some cases.
• Illumination: Adequate illumination is essential for clear imaging. Optical microscopes use various light sources, such as incandescent bulbs, halogen lamps, or LED lights. Electron microscopes use electron beams for illumination, which requires a high - vacuum environment to prevent the electrons from scattering due to air molecules.
• Adjustability: Microscopes have various adjustable components. The focus can be adjusted to bring the specimen into a clear view. The stage, where the specimen is placed, can be moved in different directions to scan the specimen. In some advanced microscopes, the lenses can be changed to achieve different magnifications, and the illumination intensity can also be adjusted.

Types of the Microscope

• Optical Microscopes:
  • Compound Microscope: This is the most common type of optical microscope. It uses multiple lenses, including an objective lens and an eyepiece, to magnify the specimen. It can be used for a wide range of biological and material studies.
  • Stereo Microscope: Also known as a dissecting microscope, it provides a three - dimensional view of the specimen. It has two separate optical paths for each eye, allowing for better depth perception. Stereo microscopes are often used for dissecting specimens, examining small objects, and in quality control processes.
  • Polarizing Microscope: This type of microscope is used to study materials that exhibit birefringence, such as certain minerals and biological tissues. It uses polarizing filters to analyze the polarization of light passing through the specimen, providing information about the orientation and structure of the sample.
• Electron Microscopes:
  • Transmission Electron Microscope (TEM): As mentioned earlier, TEMs are used to study the internal structure of specimens. The specimen needs to be extremely thin, usually less than 100 nanometers, so that the electron beam can pass through it. TEMs are widely used in biology, materials science, and nanotechnology to study the ultrastructure of cells, molecules, and nanostructures.
  • Scanning Electron Microscope (SEM): SEMs are used to study the surface morphology of specimens. They provide detailed three - dimensional images of the surface by scanning the electron beam across the specimen and detecting the secondary electrons emitted. SEMs are used in various fields, including materials science, geology, and forensic science.
• Scanning Probe Microscopes:
  • Atomic Force Microscope (AFM): An AFM uses a sharp probe to scan the surface of a specimen. The interaction between the probe and the surface, such as the force between them, is measured. This allows for the imaging of the surface topography at the atomic or molecular scale. AFMs are used in materials science, biology, and nanotechnology to study the surface properties of materials.
  • Scanning Tunneling Microscope (STM): STMs are used to image the surface of conductive materials at the atomic scale. They work based on the quantum mechanical phenomenon of tunneling current. A sharp tip is brought very close to the surface of the specimen, and a voltage is applied. The tunneling current between the tip and the surface is measured, and by scanning the tip across the surface, an image of the surface atoms can be created.

Precautions for Using the Microscope

• Handling: Microscopes are delicate instruments. When moving the microscope, hold it firmly by the arm and support the base. Avoid tilting the microscope too much, especially when there is a specimen on the stage, to prevent the specimen from falling off and the lenses from being damaged.
• Lens Care: The lenses of the microscope are crucial for clear imaging. Do not touch the lenses with your fingers, as the oils and dirt from your skin can damage the lenses. Use only lens - cleaning paper and appropriate lens - cleaning solutions to clean the lenses. When changing the objective lenses, do it gently to avoid misalignment.[!--empirenews.page--]
• Specimen Preparation: For optical microscopes, ensure that the specimen is properly prepared. It should be thin enough for light to pass through, and it should be placed flat on the stage. For electron microscopes, specimen preparation is more complex and requires special techniques to make the specimen suitable for electron imaging, such as thinning, coating, and dehydration.
• Illumination: Adjust the illumination intensity according to the requirements of the specimen and the type of microscope. For optical microscopes, too much light can cause glare and make it difficult to observe the specimen clearly, while too little light can result in a dark image. In electron microscopes, the electron beam intensity needs to be carefully controlled to avoid damaging the specimen.
• Storage: When not in use, store the microscope in a clean, dry place. Cover the microscope to protect it from dust. If the microscope has a built - in light source, turn off the power to avoid overheating and damage to the bulb.

Things to Consider when Purchasing the Microscope

• Intended Use: Determine the main purpose for which you need the microscope. If it's for biological research, a compound microscope with appropriate magnifications and resolution may be sufficient. For materials science or nanotechnology research, an electron microscope or a scanning probe microscope may be required.
• Magnification and Resolution: Consider the magnification and resolution requirements. If you need to study very small details, such as the internal structure of cells or the surface of nanoparticles, a microscope with high magnification and resolution is necessary. However, higher magnification and resolution usually come with a higher cost.
• Type of Microscope: Based on your application, choose the appropriate type of microscope. Optical microscopes are more suitable for general biological and material observations, while electron microscopes and scanning probe microscopes are for more specialized and high - resolution studies. Consider factors such as the sample preparation requirements, the environment in which the microscope will be used, and the availability of technical support for the chosen type of microscope.
• Brand and Quality: Choose a well - known brand with a good reputation for quality. A high - quality microscope will be more reliable, have better optical or electron - optical performance, and offer better after - sales support. Read reviews and consult with experts or other users to get an idea of the brand's quality and reliability.
• Budget: Set a budget for your microscope purchase. Microscopes can range from relatively inexpensive student - grade optical microscopes to extremely expensive electron microscopes. Consider the features, performance, and long - term cost of ownership, including maintenance and calibration, within your budget constraints.

Terms of the Microscope

• Magnification: The ratio of the size of the image formed by the microscope to the actual size of the specimen. It is expressed as a number followed by “x”, such as 100x.
• Resolution: The minimum distance between two distinguishable points in the specimen. A lower resolution value indicates a higher ability to distinguish fine details.
• Objective Lens: The lens closest to the specimen in a microscope. It is responsible for the initial magnification of the specimen.
• Eyepiece Lens: The lens through which the observer looks. It further magnifies the image formed by the objective lens.
• Stage: The platform on which the specimen is placed for observation. It usually has mechanisms for moving the specimen in different directions.
• Illumination: The light source used to illuminate the specimen in an optical microscope or the electron beam source in an electron microscope.
• Depth of Field: The range of distance in front of and behind the specimen plane that appears in sharp focus. A smaller depth of field means that only a thin layer of the specimen is in focus at a time.