Real-time polymerase chain reaction, also known as real-time PCR or even qPCR, is used to perform not only quantitative PCR, but also qualitative identification of genetic variants in patient screening and diagnostics. Using this technique to amplify DNA for clinical diagnostics, detection targets can vary from cancer screening of known genetic variants (e.g. BRCA 1/2), bacterial infection screening, or viral infection screening - the latter which can be very challenging using past detection technologies.