Question

To observe the specific part of a tissue section under compound microscope, the contrast can be increased by:

• A. Staining
• B. Changing magnification of the microscope
• C. Changing microscope resolution
• D. Use of fluorescence dyes

Hint:

For microscopy questions, remember the key distinctions: \textbf{Magnification} makes things bigger, \textbf{Resolution} makes things clearer, and \textbf{Contrast} makes things stand out from the background. Staining is the classic way to improve contrast.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Contrast in microscopy refers to the difference in light intensity between the image and the adjacent background.
Many biological specimens, such as tissue sections, are largely transparent and have very little natural contrast, making them difficult to see under a standard bright-field microscope.
To visualize specific structures, the contrast must be enhanced.
Step 2: Detailed Explanation:


Staining: This is the most common method to increase contrast in light microscopy.
Dyes are used that selectively bind to specific cellular components (like the nucleus, cytoplasm, or cell membranes), making them colored and thus easily distinguishable from the unstained background.

Changing magnification: Increasing magnification makes the image appear larger, but it does not increase the contrast.
In fact, excessively high magnification without sufficient contrast and resolution can result in a blurry, unclear image.

Changing microscope resolution: Resolution is the ability to distinguish between two closely spaced points.
While improving resolution enhances the detail that can be seen, it does not directly increase the contrast of an unstained specimen.

Use of fluorescence dyes: This is a specific type of staining used in fluorescence microscopy, not typically in a standard compound (bright-field) microscope.
While it dramatically increases contrast, "staining" is the broader and more general correct answer applicable to compound microscopy.

Step 3: Final Answer:
Therefore, staining is the primary method to increase contrast for observing tissue sections with a compound microscope.