Which of the following statements about molecular diagnosis is correct?

Options

A. PCR can detect high amounts of viral DNA present in the diseased patient.
B. ELISA incorporates the use of a radioactive probe which is allowed to hybridise to its complementary DNA.
C. PCR is powerful technique to identify different genetic disorders and is also used in the detection of mutated genes in suspected cancer patients,
D. Recombinant DNA technology is a risky method and hence is not used in molecular diagnosis.

Answer

To solve the question regarding which statement about molecular diagnosis is correct, we can analyze each of the provided statements one by one.

### Step-by-Step Solution:

1. **Understanding Molecular Diagnosis**:
- Molecular diagnosis involves techniques that analyze biological markers in the genome and proteome. It is used to identify genetic disorders, infections, and cancers.

2. **Analyzing the Statements**:
- **Statement 1**: "PCR can detect high amounts of viral DNA present in the diseased patient."
- **Analysis**: This statement is misleading. PCR (Polymerase Chain Reaction) is not limited to detecting high amounts of viral DNA; it can amplify even small quantities of DNA. Therefore, this statement is incorrect.

- **Statement 2**: "ELISA incorporates the use of the radioactive product which is allowed to hybridize to its complementary DNA."
- **Analysis**: ELISA (Enzyme-Linked Immunosorbent Assay) typically uses enzymes or colorimetric detection methods rather than radioactive products. This statement is also incorrect.

- **Statement 3**: "PCR is a powerful technique used to identify different genetic disorders and used in the detection of the mutated genes in the suspected cancer patients with respect to the molecular diagnosis."
- **Analysis**: This statement is accurate. PCR is indeed a powerful tool in molecular diagnostics for identifying genetic disorders and detecting mutations associated with cancer. This statement is correct.

- **Statement 4**: "Recombinant DNA technology is a risky method and hence it is not used in molecular diagnosis."
- **Analysis**: This statement is incorrect. Recombinant DNA technology is widely used in molecular diagnostics, despite some associated risks. It plays a crucial role in various diagnostic applications.

3. **Conclusion**:
- Based on the analysis, the correct statement about molecular diagnosis is **Statement 3**.

### Final Answer:
The correct statement about molecular diagnosis is: **PCR is a powerful technique used to identify different genetic disorders and used in the detection of the mutated genes in the suspected cancer patients with respect to the molecular diagnosis.**

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