Real-Time PCR uses various fluorescent detection chemistries that allow you to monitor the PCR reaction as it progresses. The amount of fluorescent signal generated is directly proportional to the amount of DNA being synthesized during the PCR reaction. Data are collected at each cycle as opposed to traditional PCR, which collects data at the end of the reaction. This allows samples to be characterized by when amplification is first detected as opposed to the amount of product generated after PCR cycling. The greater the amount of the target sequence, the earlier amplification will be detected.