ABSTRACT
This chapter describes what quantitative polymerase chain reaction (qPCR) is as well as a brief history of its development. It focuses on how it is being used in precision medicine and as a companion diagnostic. Standard polymerase chain reaction (PCR) was originally described and introduced in the 1980s by K. Mullis et al. Since then PCR has been utilized to clone genes, map genes, sequence DNA, and detect gene expression. When it was first introduced, there was hope that it would be able to be utilized to quantify amounts of DNA originally present in samples. qPCR, also known as real-time PCR, is a molecular biology laboratory technique based on PCR that allows for the experimenter to identify quantities of DNA in a sample. This can allow for the detection of quantities of specific genes, or genetic sequences present. qPCR is carried out similarly to traditional PCR and extraction of genetic material from samples prior to analysis is required.
