Question

Which of the following is the best technique for detecting HIV:

• A. \( \text{Widal test} \)
• B. \( \text{Real-time PCR} \)
• C. \( \text{Polymerase chain reaction} \)
• D. \( \text{Reverse transcriptase-PCR} \)

Hint:

HIV testing methods include: 1. ELISA: For initial screening. 2. Western blot: For confirmation. 3. RT-PCR: Highly sensitive for detecting viral RNA, especially in early stages of infection.

Answer 1

The Correct Option is D

Step 1: Understanding HIV detection techniques. HIV detection requires identifying viral RNA or DNA in the patient’s blood. Among the given options, reverse transcriptase-PCR (RT-PCR) is the most specific and sensitive method. It involves converting viral RNA into complementary DNA (cDNA) using reverse transcriptase, followed by amplification using PCR. 
Step 2: Comparison with other options. - Option \( (A) \): The Widal test is used for typhoid diagnosis, not HIV. - Option \( (B) \): Real-time PCR can be used but does not specifically include the reverse transcription step essential for RNA viruses like HIV. - Option \( (C) \): Standard PCR amplifies DNA but cannot process RNA directly without reverse transcription. 
Conclusion: RT-PCR is the best technique for detecting HIV, as it specifically amplifies viral RNA, making \( (D) \) the correct answer.