Quantification of pork, chicken and beef by using a novel reference molecule.

A standard plasmid was constructed as a novel reference molecule for use in real-time quantitative PCR assays to verify the identity of beef, pork, chicken, mutton, and horseflesh. The plasmid contained a target domain of the cytochrome b (cyt b) gene and an artificial DNA sequence. Primers CO-F and CO-R, and probe CO-P were specifically designed to detect the artificial sequence. The calculated R² values of the standard curves (10³-107 copies per reaction) for the five species ranged between 0.998 and 0.999 in the quantification analysis. The constructed plasmid provides a universal method for measuring the copy number of cyt b DNA in minced meat. This method would be a useful procedure for verifying food labels.