If a bacterium stains red/pink in a Gram-staining technique, it is said to be

Options

A. Gram-positive
B. Gram-negative
C. Gram-neutral
D. None of these

Answer

**Step-by-Step Solution:**

1. **Understanding Gram Staining Technique**: The Gram staining technique is a method used to classify bacteria into two groups: Gram-positive and Gram-negative. This classification is based on the properties of their cell walls.

2. **Cell Wall Composition**:
- **Gram-positive bacteria** have a thick layer of peptidoglycan in their cell walls. This thick layer retains the initial stain (crystal violet) used in the Gram staining process.
- **Gram-negative bacteria** have a thinner peptidoglycan layer. When the crystal violet stain is applied, it is washed out during the process, and these bacteria do not retain this initial stain.

3. **Counter Staining**: After the initial staining and washing, a counter stain (safranin) is applied.
- In the case of Gram-negative bacteria, the safranin stains them red or pink because they do not retain the crystal violet stain.

4. **Conclusion**: If a bacterium stains red or pink in the Gram-staining technique, it indicates that it is a Gram-negative bacterium.

**Final Answer**: If a bacterium stains red/pink in a Gram-staining technique, it is said to be **Gram-negative**.

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