PCR基礎(chǔ)簡(jiǎn)介

Backgrand of PCR Technologies

	Real time PCR
		Real-Time PCR Process
		In real-time PCR, the detection step is combined with amplification: the amplified target nucleic acid is visualized in real time as a fluorescent signal. This signal is generated at each PCR cycle only when a specific oligonucleotide probe called a molecular beacon, linked to a fluorophore, hybridizes with the amplified target DNA. As the amount of amplified DNA increases with each round of amplification, fluorescence intensity also increases. During each PCR cycle, a real-time PCR instrument such as the iQ5 or Chromo4 system measures the fluorescence signal, and the associated software plots a graph of the fluorescence intensity versus the number of cycles.


		Real-Time PCR Quantification

		Real-time PCR is the perfect method for the quantification of a target nucleic acid in a food or water sample. After amplification of the target nucleic acid in parallel to calibrated quantification standards, the number of initial DNA copies in the sample can be automatically calculated by the real-time software without requiring any additional operations. The software simply constructs a standard curve from the values recorded for the quantification standards and plots the values for the samples against this standard curve.