Loop-Mediated Isothermal Amplification for On-Site Visual Identification of Leech Species

Leeches are a well-known animal-derived health supplement commonly used as an anticoagulation and antithrombosis agent; however, adulteration and counterfeiting are often made for illegal profits. To identify leech species, this study developed a rapid, simple, and visualized method based on loop-mediated isothermal amplification (LAMP), which relies on a specific primer set designed according to the mitochondrial DNA control region of the target species. Quantitative polymerase chain reaction (qPCR) was also employed in parallel to compare the sensitivity and confirm the primer specificity. Primer sets with high specificity were successfully screened for LAMP reactions against four common leech species on the market. All of them have produced typical amplification profiles of the target sequences in qPCR reactions with significantly lower amplification sensitivity than LAMP assay. The newly established LAMP method in this study can be accomplished within 1 h, and it could be successfully applied for on-site visual identification of mislabeling and adulteration in the leech market.