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: Core Idea:
The question concerns the necessary equipment for viewing microscopic microbial cells, like bacteria.

Step 2: Elaboration:
Microbial cells are typically a few micrometers (µm) in size, requiring high magnification for clear observation.
\[\begin{array}{rl} \bullet & \text{A standard compound light microscope is essential. A "low-power" objective (e.g., 10x) is inadequate. A "high-power" objective is needed.} \\ \bullet & \text{The highest power objective is the oil immersion lens (100x). With a 10x eyepiece, the total magnification is \(100 \times 10 = 1,000\text{X}\). } \\ \bullet & \text{This 1,000X magnification is standard for routine bacterial examination.} \\ \end{array}\]Option (3) provides the most precise and correct answer. Option (1) is correct but less specific. Option (2) is incorrect. Option (4) is wrong because 1,000X is high magnification, not low.

Step 3: Conclusion:
To examine microbial cells, a high-power microscope with approximately 1,000 X magnification is required.