[Rapid molecular identification of pseudostellariae radix]

To establish a convenient and rapid method for identification of Pseudostellariae Radix by molecular identification, the rDNA-ITS sequences of Pseudostella riaheterophylla and its adulterants had been aligned to find out specific fragment. The specific primers against the fragment were designed and the PCR amplification conditions were optimized. The fluorescence reaction of the PCR products colored by 100 x SYBR Green I was observed under UV. The concentration of reaction buffer included 5.5 μL DNA Taq polymerase premix, 10 pmol Tzs-2F and 10 pmol Tzs-2R, 20-80 ng template DNA, and plus double sterile distilled water to 25 μL. The PCR thermal profile was as follows: predenaturation at 95 degrees C for 1 min, followed by 30 cycles of denaturation at 95 degrees C for 5 seconds, primer annealing and extension at 56 degrees C for 15 seconds, then it was extension at 72 degrees C for 30 seconds. The fluorescence reaction of Pseudostellariae Radix showed green fluorescence, while adulterants had not. Extraction, amplification DNA and all steps of molecular identification could be completed successfully in 40 minutes. The approach could amplify DNA template of Pseudostellariae Radix specificity, and its product with 1 μL 100 x SYBR Green I could engender green fluorescence under UV. The method was simple and accurate, so it could be used for identification of Chinese traditional medicine.