The stain used to visualise mitochondria is

Options

A. Fast green
B. Safranin
C. Aceto carmine
D. Janus green

Answer

To answer the question, "The stain used to visualize mitochondria is," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**: Mitochondria are organelles within cells that are crucial for energy production. To visualize them under a microscope, specific stains are used that can selectively bind to these organelles.

2. **Identifying the Stains**: The options provided are:
- Fast Green
- Safranin
- Acetocarmine
- Janus Green

3. **Analyzing Each Stain**:
- **Fast Green**: This stain is primarily used to color the cytoplasm of cells, not specifically for mitochondria.
- **Safranin**: This stain is used for staining chromosomes and nuclei, giving them a red color. It does not target mitochondria.
- **Acetocarmine**: This stain is also used for chromosomes, reacting with genetic material to provide a distinct color. It is not used for mitochondria.
- **Janus Green**: This stain is specifically known for its ability to visualize mitochondria. It reacts with the components within mitochondria, making them visible under a microscope.

4. **Conclusion**: Based on the analysis, the correct answer is **Janus Green**, as it is the stain specifically used to visualize mitochondria.

### Final Answer:
The stain used to visualize mitochondria is **Janus Green**.