Which one of the following techniques are used for early detection of…

The correct answer is Option (2) → PCR and ELISA

Early diagnosis means finding a disease while the pathogen is still very low in number, before the symptoms appear.

Option (1) PCR and serum analysis — Incorrect. PCR (polymerase chain reaction) fits, but serum analysis is a conventional method that cannot detect early.

Option (2) PCR and ELISA — Correct. PCR (polymerase chain reaction) amplifies the pathogen’s nucleic acid, and ELISA (enzyme linked immuno-sorbent assay) detects its antigens or the antibodies against it.

Option (3) ELISA and urine analysis — Incorrect. ELISA (enzyme linked immuno-sorbent assay) fits, but urine analysis is conventional.

Option (4) Urine and serum analysis — Incorrect. Both are conventional methods that NCERT says cannot detect early.

NCERT Extract:
Molecular Diagnosis – “… You know that for effective treatment of a disease, early diagnosis and understanding its pathophysiology is very important. Using conventional methods of diagnosis (serum and urine analysis, etc.) early detection is not possible. Recombinant DNA technology, Polymerase Chain Reaction (PCR) and Enzyme Linked Immuno-sorbent Assay (ELISA) are some of the techniques that serve the purpose of early diagnosis.”