Question

Assertion: Janus green, methylene blue and neutral red are called the vital stains.
Reason: They stain the cell organelles without killing the cell.
A. Both assertion and Reason are correct and Reason is the correct explanation for assertion.
B. Both assertion and Reason are correct and Reason is not the correct explanation for assertion.
C. Assertion is correct but Reason is incorrect.
D. Assertion is incorrect but Reason is correct.

Answer 1

Hint: Vital staining is a technique in which the harmless dye is used to stain the living tissues for the observation under a microscope. The vital staining is very useful in diagnostic and surgical techniques.

Complete Answer:
To solve this question, we must know about techniques of vital staining.
Vital staining is the use of certain dyes which do not cause any harm to the living cells. This is used to stain the organelles which are present in the living cells.

The staining is done by two ways-
1. Supra vital staining- In this the living cells are removed from the organism.
2. Intravital staining- It is done by injecting the stain in the body.

Most commonly used vital stains are:
a. Janus Green- It is a basic dye and used to stain tissues.
b. Methylene blue- It is used to stain DNA and nucleus.
c. Neutral red- it is used to stain lysosome red.

Thus the correct answer is (A).

Note: The staining enhances the visualisation of cell and organelles under a microscope. The cells are stained in order to study the metabolic processes and also to study the living and dead cell in the given sample.