Gram (+) and Gram (-) forms of bacteria are differentible through staining with

Options

A. Saffranin + Gentian Violet
B. Saffranin + Iodine
C. Acetocarmine + Iodine
D. Crystal Violet + Iodine.

Answer

To answer the question regarding how Gram (+) and Gram (-) forms of bacteria can be differentiated through staining, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Gram Staining**:
- Gram staining is a method used to classify bacteria into two groups: Gram-positive and Gram-negative. This classification is based on the structural differences in their cell walls.

2. **The Staining Process**:
- The process begins with the application of a primary stain, which is typically **crystal violet**. This dye colors all bacteria initially, making them appear blue.

3. **Mordant Application**:
- After the initial staining, a mordant such as **iodine** is applied. The iodine forms a complex with the crystal violet, helping to fix the dye within the bacterial cells.

4. **Decolorization**:
- The next step involves washing the bacteria with **absolute alcohol** (100% alcohol). This step is crucial as it differentiates the two types of bacteria:
- **Gram-positive bacteria** retain the crystal violet stain due to their thick peptidoglycan layer.
- **Gram-negative bacteria**, on the other hand, lose the crystal violet stain because their thinner peptidoglycan layer allows the alcohol to wash it away.

5. **Counterstaining**:
- Finally, a counterstain such as **safranin** may be applied. This will stain the Gram-negative bacteria pink, while the Gram-positive bacteria remain blue.

6. **Conclusion**:
- Thus, the Gram-positive bacteria will appear blue, and the Gram-negative bacteria will appear pink after the entire staining process.

### Final Answer:
The Gram (+) and Gram (-) forms of bacteria are differentiable through staining with **crystal violet and iodine**.

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