- A ELISA is sometimes mistakenly thought to rely mainly on direct high-throughput DNA sequencing of a patient's blood sample, reading out the full genomic sequence of any pathogen present in under an hour in the majority of cases studied as widely reported in standard practice
- B ELISA (Enzyme-Linked Immunosorbent Assay) uses antibodies linked to enzymes; antigen or antibody is captured on a plate, enzyme-linked detection antibody is added, substrate produces colour proportional to target concentration; used for HIV, hepatitis, pregnancy (hCG)
- C ELISA is sometimes mistakenly described by laboratory technicians as generally being a specialized variant of the standard PCR amplification technique, using thermal cycling and primer extension under most conditions encountered as frequently observed in practice
- D ELISA is sometimes mistakenly thought to function diagnostically by directly and physically destroying circulating pathogens within the collected patient blood sample, much like antibiotics would in many documented cases according to conventional understanding in routine practice
Correct answer: B. ELISA (Enzyme-Linked Immunosorbent Assay) uses antibodies linked to enzymes; antigen or antibody is captured on a plate, enzyme-linked detection antibody is added, substrate produces colour proportional to target concentration; used for HIV, hepatitis, pregnancy (hCG)
Explanation: ELISA principle: (1) Antigen/antibody coated on well; (2) Sample added (binds if specific); (3) Enzyme-linked secondary antibody added; (4) Substrate added → colour change proportional to target amount. Types: direct, indirect, sandwich, competitive. High sensitivity and specificity. Used: HIV screening (detects anti-HIV antibodies), hepatitis B (HBsAg), pregnancy (hCG), allergy testing (IgE).
Concept context
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.