Question

For the examination of microbial cells we require the use of?

• A. High-power microscope
• B. Low-power microscope
• C. High-power microscope at a magnification of about 1,000 X
• D. Low-power microscope at a magnification of about 1,000 X

Hint:

In microbiology labs, the term "oil immersion" is synonymous with viewing bacteria. The oil is used with the 100x objective lens to achieve the 1000x total magnification needed to see these tiny cells clearly.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The question asks about the specific equipment needed to visualize microbial cells, such as bacteria, which are microscopic.

Step 2: Detailed Explanation:
Microbial cells are typically only a few micrometers (µm) in size. To see them clearly, a high level of magnification is required.
\[\begin{array}{rl} \bullet & \text{A standard compound light microscope is used. A "low-power" objective (e.g., 10x) is insufficient to resolve individual bacterial cells. A "high-power" objective is necessary. } \\ \bullet & \text{The highest power objective on a standard light microscope is the oil immersion lens, which has a magnification of 100x. When combined with the 10x magnification of the eyepiece (ocular lens), it provides a total magnification of \(100 \times 10 = 1,000\text{X}\). } \\ \bullet & \text{This 1,000X magnification is the standard and necessary level for routine examination of most bacteria. } \\ \end{array}\] Option (3) is the most precise and correct answer. Option (1) is correct but less specific. Option (2) is incorrect. Option (4) is contradictory as 1,000X is high magnification, not low.

Step 3: Final Answer:
For the examination of microbial cells, we require the use of a high-power microscope at a magnification of about 1,000 X.