Electron Microscopes
Electron microscopes use electrons to form an image, resulting in increased resolution and a more detailed image. The beam of electrons has a much smaller wavelength than light, allowing an electron microscope to resolve two objects that are extremely close together. The maximum resolution of electron microscopes is around 0.002μm/0.2nm, making them suitable for observing small organelles such as ribosomes, the endoplasmic reticulum, or lysosomes. They have a maximum useful magnification of x 1,500,000 and are available in two types: Transmission electron microscopes (TEMS) and Scanning electron microscopes (SEMs).
Optical (Light) Microscopes
Optical microscopes use light to form an image. However, the use of light limits their resolution. The maximum resolution of optical microscopes is 0.2 μm or 200nm, and they can only observe eukaryotic cells, nuclei, and possibly mitochondria and chloroplasts. Optical microscopes have a maximum useful magnification of x 1500, and they can only be used with very thin specimens or thin sections of the object being observed. Additionally, they cannot be used to observe live specimens, and a lengthy treatment is required to prepare specimens.
Laser Scanning Confocal Microscopes
Laser scanning confocal microscopes are a new technology that requires the cells being viewed to be stained with fluorescent dyes. They can be used on thick or 3D specimens, and they allow the external 3D structure to be observed. However, the process of obtaining an image is very slow, and a lot of time is needed. There is also a potential for the laser to cause photodamage to the cells.
Advantages of TEMS and SEMS
Transmission Electron Microscopes (TEMS) give high-resolution images, allowing the internal structures within cells or organelles to be seen. On the other hand, Scanning Electron Microscopes (SEMs) can produce 3D images that show the surface of the specimen.
Disadvantages of TEMS and SEMS
The disadvantages of TEMS include being unable to distinguish between objects closer than half a wavelength, and they can only be used with very thin specimens or thin sections of the object being observed. While SEMS have lower resolution than TEMS and cannot be used to observe live specimens.
Advantages and Disadvantages of Laser Scanning Confocal Microscopes
Laser scanning confocal microscopes have the advantage of allowing the external 3D structure to be observed and producing high resolution images. However, they are a slow process and could potentially cause photodamage to the cells.
In conclusion, each type of microscope has its own set of advantages and disadvantages. It is important to consider the specific needs of the observation when selecting the appropriate microscope to use.
Note: This improved text provides a clearer and structured explanation of electron microscopes, optical microscopes, and laser scanning confocal microscopes. It also highlights the advantages and disadvantages of each type of microscope for better understanding and comparison.
