The separated DNA fragment after electrophoresis is observed by treating with ethidium bromide by exposed in u - V radiaiton which give rise

Options

A. Orange color
B. Blue color
C. Red color
D. Purple color

Answer

**Step-by-Step Solution:**

1. **Understanding Electrophoresis**: Electrophoresis is a technique used to separate DNA fragments based on their size. When an electric current is applied, negatively charged DNA fragments move towards the positive electrode.

2. **Preparation of Agarose Gel**: A gel is prepared using agarose, which acts as a medium for the DNA fragments to travel through. Wells are created at one end of the gel to load the DNA samples.

3. **Loading DNA Samples**: The DNA samples are loaded into the wells of the agarose gel. Since DNA is negatively charged, it will migrate towards the positive end when the electric current is applied.

4. **Running the Gel**: The electric current is turned on, causing the DNA fragments to move through the gel. Smaller fragments move faster and further than larger ones, resulting in separation.

5. **Staining with Ethidium Bromide**: After electrophoresis, the gel is treated with ethidium bromide, a fluorescent dye that intercalates between the bases of DNA. This step is crucial because DNA fragments are not visible to the naked eye.

6. **Exposure to UV Radiation**: The gel is then exposed to ultraviolet (UV) light. Ethidium bromide fluoresces under UV light, emitting an orange color.

7. **Observation of Results**: The separated DNA fragments can now be observed as distinct orange-colored bands on the gel, indicating the presence of DNA.

**Final Answer**: The separated DNA fragment after electrophoresis is observed by treating it with ethidium bromide and exposing it to UV radiation, which gives rise to orange-colored bands.

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