What type of microscope must be used to visualize viruses?

• A. Fluorescence microscope
• B. Light microscope
• C. Confocal microscope
• D. Electron microscope

Answer: (D)

Verified step by step guidance

1. Understand the size of viruses: Viruses are extremely small, typically ranging from 20 to 300 nanometers in size, which is much smaller than most cells and bacteria.
2. Learn about the limitations of light microscopes: Light microscopes, including fluorescence and confocal microscopes, use visible light to illuminate samples. The resolution limit of light microscopes is about 200 nanometers, which is not sufficient to clearly visualize most viruses.
3. Explore the capabilities of electron microscopes: Electron microscopes use a beam of electrons instead of light to achieve much higher resolution, allowing them to visualize structures as small as a few nanometers.
4. Differentiate between types of electron microscopes: There are two main types of electron microscopes—transmission electron microscopes (TEM) and scanning electron microscopes (SEM). TEMs are typically used to view the internal structure of viruses, while SEMs are used for surface details.
5. Conclude with the appropriate choice: Given the need for high resolution to visualize viruses, an electron microscope is the appropriate tool for this purpose.