Although there are thirteen varieties of ginseng, only two are commercialised in herbal products - Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius). Ginseng root is a popular medicinal plant with a global estimated value of USD 2.1 billion. The two varieties are highly valued in their respective markets, and intentional mixing often takes place for economic reasons as does potential adulteration with other plants. Therefore, this study developed a DNA assay to identify the two species and distinguish them from potential adulterants. Preparation of the milled ginseng root degrades the DNA, which makes barcoding or sequencing not practical assays to identify the two types of ginseng. Therefore, specific hydrolysis probe-qPCR for the two varieties of ginseng was developed, and validated on a portable qPCR instrument using 9 authentic samples of P. ginseng and 10 authentic samples of P. quinquefolius, with 19 authentic samples of other potential adulterating plants. The assay was found to be 100% specific for each variety of ginseng with no cross reaction with the 19 other plants. The assay was then tested with 42 commercial herbal products of P. ginseng and 40 commercial products of P. quinquefolius purchased in China, Canada and the USA, which found that 2 of the P. ginseng products were incorrectly labelled and were P. quinquefolius.
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