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Panax ginseng products can be adulterated with materials from other Panax species. The purpose of this study is to provide a rapid P. ginseng authentication method for simultaneous identification of P. ginseng and detection of adulteration in ginseng products at different processing stages. First, a tetra-primer ARMS–PCR assay was designed based on a single-nucleotide polymorphism (SNP) within the trnL-trnF region and was tested at 28 PCR cycles with DNA extracted from Botanical Reference Materials (BRMs). Next, 5´ end random nucleotide and 3´ terminus phosphonothioates linkage modifications were incorporated into the inner primers to improve sensitivity and specificity at 40 PCR cycles. Finally, the modified assay was validated using characterized market ginseng materials and the detection limit was determined. The modified tetra-primer ARMS–PCR assay can achieve the desired sensitivity and specificity using one set of reaction conditions in ginseng materials at different stages. In validation, it was able to correctly identify target species P. ginseng and differentiate it from closely related species. This study suggests that the modified tetra-primer ARMS–PCR assay can be used for the rapid, species identity authentication of P. ginseng material in ginseng products. This assay can be used to complement chemical analytical methods in quality control, so both species identity and processing attributes of ginseng products can be efficiently addressed.

Background: A requirement of current good manufacturing practices for dietary supplements is that manufacturers must identify their dietary ingredients. DNA-based methods can provide species-level authentication that may sometimes be difficult to achieve using conventional morphological and chemical analysis methods. However, because of varying levels of DNA degradation in botanical materials, many commercial tests fail to generate consistent test results across all types of botanical materials. AOAC published guidelines for validation of botanical identification methods and proposed probability of identification (POI) as a method performance parameter. However, few DNA-based botanical authentication methods in the literature follow these guidelines and evaluate POI. Objective: To provide a targeted PCR method validation example that follows AOAC guidelines for validation of botanical identification methods. Methods: Using Matricaria chamomilla (chamomile) as an example, we performed a single-laboratory validation for a targeted PCR method that aimed to identify both raw and processed chamomile materials. The performance parameters of the test were evaluated by carrying out an inclusivity/exclusivity study and a Specified Superior Test Material/Specified Inferior Test Material study to demonstrate that the method’s POI meets industry requirements. Results: The chamomile samples were identified by the method and achieved a POI greater than 0.9 with respect to all types of chamomile botanical materials. Conclusions: The method was validated for DNA-based identification of raw and processed chamomile materials, such as sterilized powders and extracts. Highlights: This work will provide insight for laboratories and manufacturers that aim to develop and validate DNA-based botanical identification methods.

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