Expand the following (a) PCR (b) ELISA (c) DNA

Explanation

**Step-by-Step Text Solution:**

1. **Expand PCR:**
- PCR stands for **Polymerase Chain Reaction**. It is a technique used to amplify small segments of DNA, making millions of copies of a specific DNA sequence. This process occurs in vitro, meaning it takes place outside of a living organism.

2. **Expand ELISA:**
- ELISA stands for **Enzyme-Linked Immunosorbent Assay**. This is a laboratory technique used to detect and quantify proteins, antibodies, or hormones in a sample. It is commonly used for diagnosing diseases by identifying specific antibodies in a person's blood that respond to pathogens.

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