RESUMO
Ophiocordyceps sinensis is a valuable traditional Chinese medicine with a high market price. In this study, a polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method based on 2 enzymes was developed to distinguish O. sinensis from 6 common counterfeit species. To verify the applicability of this method, we experimentally tested O. sinensis organisms, tablet preparations made from O. sinensis, and cultured mycelia isolated from O. sinensis. To validate the results from this PCR-RFLP method, all real samples were identified by internal transcribed spacer sequencing. This is, to our knowledge, the first time the PCR-RFLP method has been applied to identify O. sinensis. The selection of 2 restrictive enzymes for identification dramatically improved the accuracy and efficiency of this method. It is the great advantage of this method that sampling from either of 2 parts of O. sinensis-the fruiting body or the caterpillar body-would not cause any difference in the final experimental results. Therefore, this method is not only feasible for testing crude drugs of O. sinensis but it is also useful when the crude drugs are broken down into powder or made into tablets, demonstrating the promising prospect of application in quality control.