Select the correct sequence for gram staining procedure.

Options

A. Gentian violet, Alcohol, Iodine solution, Safranin
B. Crystal violet, KI solution , Alcohol,Safranin
C. Crystal violet, Safranin , KI solution , Alcohol
D. Crystal violet, Alcohol, KI solution, Safranin

Answer

To determine the correct sequence for the gram staining procedure, we need to follow the established steps involved in the process. Here’s the step-by-step solution:

### Step-by-Step Solution:

1. **Crystal Violet Staining**: The first step in the gram staining procedure is to apply crystal violet, which is a primary stain. This dye penetrates the bacterial cell walls and stains all cells purple.

2. **Iodine Treatment**: After staining with crystal violet, the next step is to treat the cells with iodine solution (often potassium iodide). The iodine acts as a mordant, forming a complex with the crystal violet that helps to lock the dye into the cells.

3. **Decolorization with Alcohol**: The third step involves washing the cells with alcohol (or acetone). This step is crucial as it differentiates between gram-positive and gram-negative bacteria. Gram-positive bacteria retain the crystal violet-iodine complex and remain purple, while gram-negative bacteria lose the dye and become colorless.

4. **Counterstaining with Safranin**: Finally, a counterstain, usually safranin, is applied. This stains the decolorized gram-negative bacteria pink, allowing for differentiation between the two types of bacteria.

### Correct Sequence:
The correct sequence for the gram staining procedure is:
1. Crystal Violet
2. Iodine Solution (Potassium Iodide)
3. Alcohol (Decolorization)
4. Safranin

### Conclusion:
Thus, the correct answer is the second option provided in the question.

---