1. Principle
July 25, 2017
The principle
of SYBR-based real-time PCR is a standard PCR reaction carried out in the presence of a dye, SYBR, which fluorescence when intercalated in the DNA helix.
1.1 (PE Biosystems)
The fluorescence will increase as the amount of the PCR product increases and is quantified after each completed PCR cycle.
The cycle at which the fluorescence exceeds a detection threshold, the Ct (threshold cycle) correlates with the number of target cDNA molecules present in the added cDNA. Therefore, by comparison to a calibration curve, it is possible to quantify in absolute amounts the number of target molecules in cDNA samples.