Write one use of PCR technique.

Explanation

### Step-by-Step Solution:

1. **Understand PCR**: PCR stands for Polymerase Chain Reaction. It is a technique used to amplify (replicate) a specific segment of DNA outside of a living organism (in vitro).

2. **Identify a Use of PCR**: One significant application of PCR is in the field of medical diagnostics.

3. **Explain the Diagnostic Use**: PCR can be utilized to diagnose infections caused by pathogens, such as bacteria and viruses. For example, it is instrumental in diagnosing diseases like AIDS, which is caused by the Human Immunodeficiency Virus (HIV).

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