Experimental study on the detection of Gastrodia elata by enzymatic recombinase amplification and immunochromatography.

OBJECTIVE: The objective of this research is to develop two methodologies, Enzymatic recombinase amplification (ERA) and Polymerase Chain Reaction (PCR) coupled with Lateral Flow Dipstick (LFD), for the swift authentication of Gastrodia elata. METHODOLOGY: Primers and nfo probes for the ERA of Gastrodia elata were developed based on the ITS2 genome sequences of Gastrodia elata and its counterfeits. Specific primers for the PCR analysis of Gastrodia elata were generated using the NCBI (National Center for Biotechnology Information) online platform. Through experimental validation, the optimal reaction system and conditions for both methodologies were established, and their efficacy was assessed. RESULTS: The methodologies developed herein are applicable for the targeted analysis of the medicinal species, Gastrodia elata. The sensitivity of the ERA-LFD detection method matched that of the conventional PCR-LFD approach, recorded at 1 ng µL-1. Consistency was observed in the results across three replicates of visualization test strips for both techniques. Upon evaluation, both the PCR-LFD and ERA-LFD methods demonstrated a total compliance rate of 100 %. CONCLUSION: The ERA-LFD and PCR-LFD methods facilitate reduced detection times and offer visual results. These techniques are particularly effective for on-site detection and quality control in the authentication of Gastrodia elata within traditional Chinese medicine markets and at the primary level of healthcare provision.

Multiplex-PCR method application to identify duck blood and its adulterated varieties.

This study applied and validated the Multiplex-PCR method to identify the authenticity of duck blood and four common adulterated animal blood varieties. To this end, the genomic DNAs of duck blood and its counterfeit products were extracted using an efficient high-throughput extraction method. Specific primers were designed using the cytochrome b gene. The reaction system and conditions of a multiplex (namely, Five-plex) PCR were optimized, and the proposed methodology was verified, proving its good specificity, repeatability, and sensitivity. The Five-plex PCR system detected nine duck blood samples sold in the local market, revealing the adulteration of duck blood products. The Multiplex-PCR system can accurately and quickly detect adulterated animal blood in duck blood products, effectively finding counterfeits and identifying the authenticity of genuine duck blood products.

An experimental study on the visual identification of Fritillaria ussuriensis based on LAMP and nucleic acid colloidal gold technique.

Fritillaria ussuriensis Maxim is one of the traditional Chinese valuable herbs, which is the dried bulb of Fritillaria, a plant of the lily family. The identification of authenticity about F. ussuriensis is still technically challenging. In this study, visual identification was performed by ring-mediated isothermal amplification and nucleic acid colloidal gold techniques. Firstly, multiple sequence comparative analysis was performed by DNAMAN to find the differential sites of F. ussuriensis and its mixed pseudo-products, and the specific identification primers of F. ussuriensis were designed. Genomic DNA was extracted by the modified CTAB method, and the reaction system and reaction conditions were optimized to construct LAMP for the visual detection of F. ussuriensis, meanwhile, the genuine product was cloned and the extracted plasmid was sequenced. The specificity and sensitivity were detected, and also verified by nucleic acid colloidal gold method, and 20 commercially available samples were tested. The extracted DNA met the requirements of the experiment, and the genuine F. ussuriensis PCR product titrated on a test strip showed two bands on the T and C lines, while the counterfeit and negative control showed only one band on the C line, which matched the LAMP results. The specificity was 100 %, and the sensitivity of LAMP assay was up to 0.01 ng µL-1, while that of colloidal gold assay was 0.1 ng µL-1, thus the LAMP assay had high sensitivity. 14 out of 20 commercially available samples of F. ussuriensis were qualified, and 6 were unqualified, and the results of the two methods of identification were consistent. In this study, the combined detection method of LAMP and colloidal gold for nucleic acid was established to be specific, rapid, precise and visualized, which can provide a new technical idea for the detection of F. ussuriensis.