What should I use as a standard for absolute quantification in real-time PCR?
FAQ ID -1085

For quantification of RNA, we strongly recommend using RNA molecules as standards. Use of in vitro transcripts as standards takes into account the variable efficiency of the RT reaction. An alternative to the use of in vitro transcripts as RNA standards is the use of a defined RNA preparation (e.g., from a cell line or virus preparation), for which the absolute concentration of the target has already been determined.

For quantification of DNA, several types of DNA can be used, such as plasmids, PCR products, or genomic DNA.

For more information, see Appendix E 'Generating Standard Curves' in the QuantiTect Probe PCR Handbook.