Which of the following techniques is used to separate proteins?

Options

A. Gel electrophoresis
B. Isoelectric focusing
C. Polymerase chain reaction
D. Ion-exchange chromatography

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the technique used to separate proteins from a list of options provided.

2. **Analyzing the Options**:
- **Gel Electrophoresis**: This is a laboratory method used to separate mixtures of DNA, RNA, or proteins based on their size, mass, and charge. The molecules are pushed through an electric field in a gel matrix, allowing for the separation of proteins.
- **Isoelectric Focusing**: This technique is primarily used for the analysis and purification of proteins by measuring their isoelectric points (pI). It does not separate proteins in the same way as gel electrophoresis.
- **Polymerase Chain Reaction (PCR)**: PCR is a technique used to amplify DNA, creating multiple copies of a specific DNA segment. It is not used for protein separation.
- **Ion Exchange Chromatography**: This method retains molecules based on ionic interactions with a stationary phase. While it can be used in protein purification, it does not separate proteins in the same manner as gel electrophoresis.

3. **Conclusion**: Among the options provided, **Gel Electrophoresis** is the technique that is specifically used to separate proteins.

**Final Answer**: Gel Electrophoresis is the technique used to separate proteins.

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