A polymerase is any enzyme that catalyzes the formation of DNA or RNA molecules from deoxyribonucleotides and ribonucleotides, respectively.

Polymerase chain reaction (PCR) is a technique of molecular genetics in which a particular sequence of DNA can be isolated and amplified sufficiently to enable genetic analysis. The technique may be used, for example, in the identification of viruses in tissue samples, e.g., human papillomavirus in cervical smears.