Rapid identification of Dendrobium officinale using Loop-Mediated Isothermal Amplification (LAMP) method

Dendrobium officinale is not only an ornamental plant, but also a valuable medicinal herb that is widely used in traditional Chinese medicine. However, distinguishing D. officinale from other Dendrobium species is usually a difficult task. In this study, we developed a rapid identification protocol for D. officinale using the loop-mediated isothermal amplification (LAMP) method. A set of primers were specifically designed to detect a modified internal transcribed spacer region of D. officinale at 65 °C within 40 min after adding SYBR® Green I, which was used for the detection of D. officinale. Unlike commonly used adulterants, reaction mixtures containing D. officinale DNA changed from orange to green, and this color change was easily observed with the naked eye. Thus, this methodology can be used to accurately differentiate D. officinale from other Dendrobium species, is quick as all D. officinale samples were amplified within 40 min, and specific as samples of the adulterants were not amplified. The specificity of this LAMP-based method was confirmed by testing 17 samples of D. officinale and 32 adulterant samples from other Dendrobium species. This LAMP-based rapid identification method does not require expensive equipment or specialized techniques and can be used in field surveys for accurate and fast on-site identification.