Application of LightCycler polymerase chain reaction and melting curve analysis to the authentication of the traditional Chinese medicinal plant Cimicifuga foetida.

DNA sequence analysis of rDNA internal transcribed spacer (ITS) and fluorescence melting curve analysis of LightCycler real-time polymerase chain reaction products were exploited for their applications in the authentication of the traditional Chinese medicinal plant Cimicifuga foetida from four substitutes: C. heracleifolia, C. dahurica, C. acerina, and C. simplex. According to the melting temperature--which is a function of the GC/AT ratio, length, and nucleotide sequences of the amplified product--C. foetida was differentiated from C. heracleifolia, C. dahurica, C. acerina, and C. simplex. Melting curve analysis offers a rapid and reliable method for the authentication of the traditional Chinese medicinal plant C. foetida.