PCR: Detection of Pathogens Early — NEET Biology
📚 Practice ConceptPresence of a pathogen (bacteria, viruses, etc.) is normally suspected only when the pathogen has produced a disease symptom. By this time the concentration of pathogen is already very high in the body. However, very low concentration of a bacteria or virus (at a time when the symptoms of the disease are not yet visible) can be detected by amplification of their nucleic acid by PCR. Can you explain how PCR can detect very low amounts of DNA? PCR is now routinely used to detect HIV in suspected AIDS patients. It is being used to detect mutations in genes in suspected cancer patients too. It is a powerful technique to identify many other genetic disorders.
Which of the following statements regarding Polymerase Chain Reaction (PCR) in molecular diagnosis are NOT correct? S1. PCR can amplify any type of nucleic acid, including RNA, directly without prior conversion. S2. It is routinely employed for early detection of HIV infection, even when viral load is very low. S3. PCR relies on antigen-antibody interactions for identifying specific pathogens. S4. Mutations in genes of suspected cancer patients can be precisely identified by PCR analysis. S5. The technique can only detect pathogens when symptoms of the disease are clearly visible due to high pathogen concentration.
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