In gel electrophoresis, separated DNA fragments can be visualized with the help of:

Options

A. Ethidium bromide in UV radiation
B. Acetorarmine in UV radiation
C. Ethidium bromide in infrared radiation
D. Acetocarmine in bright blue light

Answer

**Step-by-Step Solution:**

1. **Understanding Gel Electrophoresis**: Gel electrophoresis is a technique used to separate DNA fragments based on their size. The DNA is placed in a gel matrix (usually agarose) and subjected to an electric field, causing the negatively charged DNA to migrate towards the positive electrode.

2. **Need for Visualization**: After the DNA fragments have been separated, it is essential to visualize them to analyze the results. This is because the DNA fragments are not visible to the naked eye.

3. **Use of Staining Agents**: To visualize the separated DNA fragments, specific staining agents are used. These agents bind to the DNA and allow it to be seen under certain types of light.

4. **Identifying the Correct Staining Agent**: Among the options provided:
- Ethidium bromide (EB) is a commonly used fluorescent dye that intercalates between the base pairs of DNA.
- Acetocarmine is another dye but is not typically used for visualizing DNA in gel electrophoresis.

5. **Fluorescence Under UV Light**: Ethidium bromide emits fluorescence when exposed to ultraviolet (UV) light. This property allows the DNA bands to be visualized as bright bands against a dark background when the gel is illuminated with UV light.

6. **Conclusion**: Therefore, the correct answer to the question is that separated DNA fragments can be visualized with the help of ethidium bromide in UV radiation.

**Final Answer**: Ethidium bromide in UV radiation.

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