Which of the following technique is not used for early diagnosis of disease?

Options

A. Polymerase chain reaction
B. Recombinant DNA technology
C. Enzyme linked immuno sorbent assay
D. Conventional method

Answer

To determine which technique is not used for early diagnosis of disease, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding the Techniques**:
- We need to review the four techniques mentioned in the options: Polymerase Chain Reaction (PCR), Recombinant DNA Technology (R-DNA), Enzyme-Linked Immunosorbent Assay (ELISA), and Conventional Methods.

2. **Analyzing Polymerase Chain Reaction (PCR)**:
- PCR is a technique used to amplify DNA. It allows for the detection of pathogens at very low concentrations, making it useful for early diagnosis of diseases such as HIV. Therefore, PCR is used for early diagnosis.

3. **Analyzing Recombinant DNA Technology (R-DNA)**:
- R-DNA technology involves combining DNA from different species to create new genetic combinations. This technology can assist in diagnosing genetic diseases early. Thus, R-DNA technology is also used for early diagnosis.

4. **Analyzing Enzyme-Linked Immunosorbent Assay (ELISA)**:
- ELISA is based on antigen-antibody reactions and can detect faulty proteins in the body. This method is effective for early diagnosis of various diseases, including infections. Hence, ELISA is used for early diagnosis.

5. **Analyzing Conventional Methods**:
- Conventional methods include serum analysis and urine tests. These methods typically provide results much later than the other techniques mentioned. They are not efficient for early diagnosis of diseases because they often require more time to yield results.

6. **Conclusion**:
- Based on the analysis, the technique that is not used for early diagnosis of disease is the **Conventional Method**. Therefore, the correct answer is option 4.

### Final Answer:
**Option 4: Conventional Method**

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