Which assay is most commonly used to detect exposure to viral pathogens in laboratory animals?

• A. PCR
• B. ELISA
• C. Culture
• D. Anal tape test

Answer: (B)

Detecting exposure to viral pathogens in laboratory animals relies on finding evidence the animal’s immune system has responded to the virus. An ELISA does this by capturing virus-specific antibodies from a serum sample and producing a measurable signal that reflects antibody levels. This makes ELISA ideal for surveillance because it can screen large numbers of animals quickly, cost-effectively, and with high throughput, indicating prior exposure even if the virus is no longer present. PCR, by contrast, looks for viral genetic material and is best for identifying current infection, not past exposure. Culture requires growing the virus and is time-consuming and less practical for routine screening, and the anal tape test is unrelated to detecting viral exposure.