Authentication of Chinese crude drug gecko by DNA barcoding.

Gekko gecko, an animal used as a valued traditional Chinese medicine, has been widely used for over 2000 years. Due to localized habitat destruction, the amount of G. gecko has dramatically decreased in recent years. As a result, more and more adulterants have been detected in the traditional medicine, which has resulted in a chaotic market. Therefore, a correct identification method is badly needed. In this study, we employed a new molecular method of DNA barcoding for discriminating gecko from its adulterants. Fifty-seven specimens of gecko and its adulterants were collected as test samples. The full-barcode and mini-barcode sequences of these specimens were separately amplified and sequenced separately. Together with other published barcode sequences, we detected that the intra-specific sequence diversity was far lower than the inter-specific diversity in G. gecko and its adulterants (3% compared with 35% in full-length barcode; 4% compared with 33.5% in mini-barcode). These results showed that both the full-length and mini-barcodes were effective for identifying gecko, which suggested that the DNA barcode could be an effective and powerful tool for identifying the Chinese crude drug gecko.