Polymerase Chain Reaction: A New Paradigm in Diagnosis

Polymerase chain reaction (PCR) amplification technique involves a process where there is denaturation and renaturation of short segments of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) sequences using DNA polymerase I enzyme. PCR consists of three major steps: denaturation, hybridization/annealing, and elongation/amplification. Since its introduction, PCR has become a useful diagnostic tool across a wide range of clinical conditions. It plays an important role in the diagnosis of infectious diseases, genetic disorders, and cancers, as well as in forensic toxicology. This chapter explores the fundamental principles of PCR, detailing its technical aspects and clinical utility. We explore the many clinical diagnostic applications of PCR, emphasizing its use in health care and accurate diagnosis of diseases. We also discuss the potential applications of PCR in the future, especially in point-of-care testing.