Which of the following techniques serve the purpose of early diagnosis than most conventional methods of diagnosis?
A. Recombinant DNA technology
B. PCR
C. ELISA

Options

A. A only
B. A & C only
C. A & B only
D. A,B,&C

Answer

To determine which techniques serve the purpose of early diagnosis better than most conventional methods, we will analyze each option provided: Recombinant DNA technology, PCR, and ELISA.

### Step-by-Step Solution:

1. **Understanding Conventional Methods**:
- Conventional diagnostic methods often involve blood or serum analysis, which may take longer to yield results. These methods typically identify diseases based on symptoms or after significant disease progression.

**Hint**: Consider how traditional methods compare in speed and efficiency to newer techniques.

2. **Analyzing Recombinant DNA Technology**:
- Recombinant DNA technology involves combining DNA from different organisms and inserting it into a host organism. This method can help in diagnosing diseases like HIV or AIDS by allowing for the replication of specific DNA sequences related to the disease.
- However, while it is useful, it may not be the fastest method for early diagnosis compared to others.

**Hint**: Think about the time required for DNA manipulation and analysis in this technique.

3. **Analyzing PCR (Polymerase Chain Reaction)**:
- PCR is a powerful technique that amplifies small segments of DNA. This amplification allows for the rapid detection of pathogens, making it a very effective method for early diagnosis.
- PCR can provide results in a matter of hours, which is significantly faster than many conventional methods.

**Hint**: Focus on how amplification of DNA can lead to quicker results in diagnostics.

4. **Analyzing ELISA (Enzyme-Linked Immunosorbent Assay)**:
- ELISA is based on the interaction between antigens and antibodies. It is a widely used method for detecting the presence of specific proteins or antibodies in a sample.
- This method is also relatively quick and can provide results faster than traditional methods, making it suitable for early diagnosis.

**Hint**: Consider how the specificity of antigen-antibody interactions can lead to rapid results.

5. **Conclusion**:
- After analyzing all three techniques, it is clear that PCR and ELISA are particularly effective for early diagnosis due to their speed and efficiency. Recombinant DNA technology, while useful, may not be as quick as the other two methods.
- Therefore, the correct answer is that both PCR and ELISA serve the purpose of early diagnosis better than most conventional methods.

### Final Answer:
**B. PCR and C. ELISA are the techniques that serve the purpose of early diagnosis better than most conventional methods.**