Which of the following techniques serve the purpose of early diagnosis ?
(A) Recombinant DNA technology
(B) PCR (C ) ELISA

Options

A. A only
B. A and C only
C. A and B only
D. all of these

Answer

To determine which techniques serve the purpose of early diagnosis, let's analyze each option provided:

### Step-by-Step Solution:

1. **Understanding Recombinant DNA Technology**:
- Recombinant DNA technology involves combining DNA from two different species and inserting it into a host organism.
- This technique can help in the early diagnosis of diseases by creating new genetic combinations that can be analyzed for specific markers related to diseases.
- **Conclusion**: This technique can be used for early diagnosis.

2. **Understanding PCR (Polymerase Chain Reaction)**:
- PCR is a technique used to amplify specific segments of DNA, allowing for the detection of pathogens even at low concentrations.
- It is particularly effective for detecting viruses such as HIV, which is crucial for early diagnosis of AIDS.
- **Conclusion**: PCR is also a technique that serves the purpose of early diagnosis.

3. **Understanding ELISA (Enzyme-Linked Immunosorbent Assay)**:
- ELISA is based on the antigen-antibody reaction, which is used to detect the presence of antigens or antibodies in a sample.
- This technique is widely used for early diagnosis of various infections and diseases by identifying specific antibodies or antigens related to the disease.
- **Conclusion**: ELISA is another technique that can be used for early diagnosis.

4. **Final Assessment**:
- All three techniques: Recombinant DNA technology, PCR, and ELISA, serve the purpose of early diagnosis.
- Therefore, the correct answer is that all techniques mentioned (A, B, and C) are applicable for early diagnosis.

### Final Answer:
All of the above techniques (A, B, and C) serve the purpose of early diagnosis.

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