Microscopes come in different sizes, each with its specific suitability. The most common categories are the light microscope and the electron microscope. Each of these microscopes has distinct features and is suitable for different purposes – from the magnification of simple objects such as living cells to complex objects such as the details of a nucleus in a cell.
A light microscope (also, optical microscope) is an optical instrument used to make objects larger in order to view their details. It uses light to illuminate the objects under view.
An electron microscope is an optical instrument that uses a beam of electrons to make objects larger for a detailed view.
|Light microscope||Electron microscope|
|Simple to use||Users require technical skills|
|Can view both live and dead specimens||Views only dead specimens|
|Poor surface view||Good surface view and internal details|
|Uses light rays to illuminate specimens||Uses a beam of electrons to view specimens|
|Lenses are made of glass||Lenses are made of electromagnets|
|Low resolving power, usually below 0.30µm.||High resolving power of up to 0.0001µm.|
|Low magnification of up to 1,500x||High magnification of up to 1,000,000x|
|Images are viewed by the eyes through the eyepiece||Images are viewed on a photographic plate or zinc sulphate fluorescent screen|
|Not used under a vacuum||Operates under a high vacuum|
|Cheap to buy and has low maintenance costs||Very expensive to buy and maintain|
A number of differences such as the source of light they use, their magnification level, cost, resolving power, among other factors sets these two types of microscopes apart from each other.
- An electron microscope is very expensive to buy and requires special environments. This makes it expensive to maintain. In addition, it requires high technical skills to use and is therefore limited to specialized use such as research. A light microscope, on the other hand, is cheap to buy and maintain. It requires no special skills to use. As a result, it is suitable for most basic functions, and is very common in schools and other learning institutions.
- While a light microscope uses light to illuminate specimens and glass lenses to magnify images, an electron microscope uses a beam of electrons to illuminate specimens and magnetic lenses to magnify images.
- The resolution (the level of image detailing) is the main difference between these two microscopes. A light microscope has a resolution of up to 0.3µm, i.e. 3 micrometers. This limits it as two close objects cannot be seen as separate. In an electron microscope, the resolution is about 0.0001µm, i.e. 0.01 nanometers. This resolution can be used in situations that require greater details, such as studying cell nuclei.
- A light microscope can be used to view both dead and live specimens. This makes it important in studying live ones. By contrast, an electron microscope cannot be used to view living specimens as it uses electrons that are destructive to life.
Here is a helpful video that discusses how different microscopes work, their various differences and the different images produced by each: