PCR (polymerase chain reaction) and qPCR (quantitative polymerase chain reaction) are two commonly used molecular biology techniques that are used to amplify and quantify DNA molecules. These techniques have revolutionized the field of molecular biology by allowing scientists to amplify and study specific regions of DNA with high sensitivity and specificity. PCR is a technique that is used to amplify a specific DNA fragment, while qPCR is a modified version of PCR that allows for the quantification of the amplified DNA in real-time. Both PCR and qPCR have a wide range of applications in research, clinical diagnosis, forensic science, and biotechnology. The use of these techniques has led to significant advancements in various fields of science, including genetics, microbiology, and medicine.