PCR detects
Polymerase chain reaction (PCR) is a technique used in molecular biology to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a paicular DNA sequenceRef: DM Vasudevan, 7th edition, page no: 638
Antigen
Antibody
Nucleic acid
All of the above
Metabolism of nucleic acids