What is the primary purpose of using stains in microbiology?

• A. To sterilize the microscope slides
• B. To prevent contamination of samples
• C. To enhance the growth rate of bacteria
• D. To increase the visibility of microorganisms under a microscope

Answer: (D)

Verified step by step guidance

1. Understand that microorganisms are often transparent or nearly invisible under a microscope due to their small size and lack of natural color.
2. Recognize that stains are chemical dyes used in microbiology to bind to specific components of microbial cells, thereby adding color to them.
3. Know that the primary purpose of staining is to increase the contrast between the microorganisms and the background, making the cells more visible and easier to study under a microscope.
4. Note that staining does not sterilize slides, prevent contamination, or enhance bacterial growth; its main role is to improve visualization.
5. Conclude that using stains allows microbiologists to observe the shape, size, and arrangement of microorganisms, which is essential for identification and analysis.