Quantitative real-time polymerase chain reaction is a technique for simultaneous amplification and product quantification of a target DNA as the process takes place in real time in a "closed-tube" system. Although this technique can provide an absolute quantification of the initial template copy number, quantification relative to a control sample or second sequence is typically adequate. The quantification process employs melting curve analysis and/or fluorescent detection systems and can provide amplification and genotyping in a relatively short time. Here we describe the properties and uses of various fluorescent detection systems used for quantification.
Keywords: Fluorescent genotyping; Hybridization probe; Intercalation probe; Minimal residual disease; Molecular beacon; Nucleic acid quantification; Polymerase chain reaction (PCR); Quantitative PCR; Real-time PCR; q-PCR.