Gel electrophoresis is a technique to separate fragments of DNA from a mixture. Some of the events of electrophoresis are given below. Arrange the events in order.
(i) Cut out DNA bands (ii) Expose to UV (ii) Force DNA to move through gel (iv) Stain DNA with ethidium bromide.

Explanation

To arrange the events of gel electrophoresis in the correct order, we need to understand the sequence of operations involved in the process. Here’s the step-by-step solution:

1. **Force DNA to move through gel**: The first step in gel electrophoresis is applying an electric field to the gel, which causes the negatively charged DNA fragments to migrate towards the positive electrode. This movement separates the DNA fragments based on their size.

2. **Stain DNA with ethidium bromide (ETBR)**: After the DNA has been separated in the gel, the next step is to stain the DNA with ethidium bromide. This dye intercalates between the bases of the DNA and allows for visualization under UV light.

3. **Expose to UV**: Once the DNA is stained, the gel is exposed to UV light. The ethidium bromide emits an orange fluorescence when exposed to UV light, making the DNA bands visible.

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