Which of the followding cannot be achieved using PCR?

Options

A. Detect HIV in ADIS suspect.
B. Detect mutations in cancer patients.
C. Detect antigen-antibody interaction
D. Detect specific minroorganisms from soil.

Answer

To determine which of the following cannot be achieved using PCR (Polymerase Chain Reaction), we need to understand the capabilities and limitations of PCR. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding PCR**:
- PCR is a technique used to amplify small segments of DNA, making millions of copies of a specific DNA sequence. This is crucial for various applications in molecular biology, including diagnostics and research.

2. **Applications of PCR**:
- **Disease Detection**: PCR can be used to detect the presence of specific pathogens, such as the HIV virus in AIDS patients, by amplifying viral DNA or RNA.
- **Genetic Mutations**: It can also help in identifying mutations in genes associated with diseases like cancer by amplifying the relevant DNA segments for analysis.
- **Microorganism Detection**: PCR can be employed to detect specific microorganisms in environmental samples, such as soil, by amplifying their unique genetic material.

3. **Limitations of PCR**:
- PCR is not designed to detect protein interactions, such as antigen-antibody reactions. This type of detection requires different techniques, such as ELISA (Enzyme-Linked Immunosorbent Assay), which is specifically used to identify and quantify proteins, including antibodies and antigens.

4. **Conclusion**:
- Based on the above analysis, the option that states "detection of antigen-antibody reaction" cannot be achieved using PCR is correct. Therefore, the answer is option 3.

### Final Answer:
The correct answer is option 3: Detection of antigen-antibody reaction cannot be achieved using PCR.

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