ELISA is used to detect viruses where the key reagent is:

Options

A. Alkaline phosphatase
B. Catalase
C. DNA probe
D. RNase

Answer

To solve the question regarding the key reagent used in ELISA for detecting viruses, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding ELISA**:
- ELISA stands for Enzyme-Linked Immunosorbent Assay. It is a laboratory technique used to detect and quantify proteins, antibodies, and hormones in a sample.

2. **Identifying Key Reagents**:
- In an ELISA test, various reagents are used, including antibodies and enzymes. The enzyme linked to the antibody is crucial for the detection process.

3. **Evaluating the Options**:
- The options given are Alkaline Phosphatase, Catalase, DNA Probe, and RNAs. We need to determine which of these is the key reagent in ELISA.

4. **Understanding Alkaline Phosphatase**:
- Alkaline Phosphatase (ALP) is an enzyme that catalyzes the removal of phosphate groups from various molecules, including proteins. This property is utilized in ELISA to produce a measurable signal.

5. **Conclusion**:
- Based on the understanding of ELISA and the role of the reagents, the key reagent used in ELISA to detect viruses is **Alkaline Phosphatase**.

### Final Answer:
The key reagent used in ELISA to detect viruses is **Alkaline Phosphatase**.

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