[Allele-specific PCR to identification of Achyranthis Bidentatae Radix and Cyathulae Radix formula granules].

To establish a robust and accuracy molecular method to identify Achyranthis Bidentatae Radix and Cyathulae Radix formula granules. ITS sequences of Achyranthes bidentata and Cyathula officinalis were aligned, specific SNPs (single nucleotide polymorphisms) were excavated, specific primers were designed and allele-specific PCR method was established. The genomic DNA was successfully extracted from the herbal medicine and its formula granules by using an improved CTAB (cetyltrimethyl ammonium bromide) method and then performed PCR with the designed primers. The 187 bp specific band could be amplified only in the presentation of C. officinalis and its granules when use of C. officinalis specific primers, whereas the 162 bp band could be amplified only in the presentation of A. bidentata and its granules when use of A. bidentata specific primers. This method was also successfully applied in the identification of commercial formula granules.