Calcined oyster is a commonly used shellfish traditional Chinese medicine in clinical practice in China. During the processing of oysters, their microscopic characteristics are destroyed, and open-fire calcination can damage the DNA of oysters, making it difficult to identify the primary source. The establishment of a specific polymerase chain reaction(PCR) method for the identification of calcined oysters can provide a guarantee for the safety and clinical efficacy of the medicine and its processed products. With Ostrea gigas as an example, the DNA extraction method of decoction pieces and formula particles of calcined oysters was improved, and high-quality DNA was obtained. Based on the specific single nucleotide polymorphism(SNP) sites of O. gigas and the other two species, the specific identification primers were designed, and the site-specific identification method of formula granules of calcined oyster(O. gigas) was established. The specificity and applicability of the method were investigated. The results showed that when the annealing temperature was 54 ℃, and the cycle was 44 times, the PCR amplified products of calcined oyster(O. gigas) and its formula granules produced a single bright identification band at 102 bp, while the other two species of oysters, O. talienwhanensis Crosse and O. rivularis Gould, had no band. In this study, DNA extraction and PCR identification of animal medicinal materials by calcination were established for the first time, which provided a tool for solving the difficult identification of calcined decoction pieces and ensuring drug safety.
Keywords: Ostrea gigas; calcined oyster; formula granule; polymerase chain reaction; single nucleotide polymorphism site.