Q21.The gold standard method used for the detection of SARS-CoV-2 infection is
(A) ELISA
(B) RT-PCR
(C) Microarray
(D) FISH
The correct answer is (B) RT-PCR. This remains the gold standard for detecting active SARS-CoV-2 infection due to its high sensitivity and specificity in identifying viral RNA.
RT-PCR converts viral RNA to cDNA and amplifies it for precise early detection, even in asymptomatic cases, outperforming other methods for confirmatory diagnosis.
Option Analysis
ELISA: Enzyme-linked immunosorbent assay detects antibodies (IgM/IgG) against SARS-CoV-2, useful for seroprevalence or past exposure but not for active infection as it misses early acute phases before antibody response.
RT-PCR: Reverse transcription polymerase chain reaction targets viral genes like N, E, S, or RdRp in samples such as nasopharyngeal swabs. It enables quantitative, highly specific RNA detection, making it the WHO-recommended reference standard.
Microarray: Hybridization-based technique for analyzing multiple genes or mutations but lacks the sensitivity and speed for routine SARS-CoV-2 RNA detection in clinical settings.
FISH: Fluorescence in situ hybridization visualizes specific nucleic acids in cells, applied in research but impractical for high-throughput viral diagnostics due to complexity and cost.
RT-PCR stands as the gold standard method for SARS-CoV-2 detection, offering unmatched sensitivity for viral RNA in respiratory samples. This technique transformed COVID-19 diagnostics by enabling rapid, specific identification of active infections.
Method Breakdown
ELISA assesses immune response post-infection, ideal for surveillance but delayed for acute cases. RT-PCR amplifies target genes like RdRp for results in hours, supporting early intervention. Microarray and FISH serve niche genomic roles without matching RT-PCR’s clinical reliability.
