Quantification of Polymerase Chain Reaction Designs to Analyze the Ancient Deoxyriboncleic Acid Samples Excavated in Xiaohe Cemetery, Xinjiang, China

Human DNA quantification has become an essential means to evaluate the preservation of ancient samples and to ensure the authentication of the results in ancient DNA research. SYBR green I real-time polymerase chain reaction (PCR) was used to quantify five samples, which were excavated in Xiaohe Cemetery, China. Three different fragment sizes (138 bp, 209 bp and 363 bp) within the mitochondrial DNA hypervariable region I (HVR-I) and the AMG gene (121/115 bp) of the nuclear DNA were analyzed. The quantification results of mitochondrial DNA showed an inverse correlation between amplicon length and amplification efficiency, and only the copy numbers of 138 bp DNA were all higher than 150 copies μ1−1. Although majority of the copy numbers of AMG gene were lower than 30 copies μl−1, STR and SNP of nuclear DNA could also be analyzed. This study also showed that tooth samples had more DNA copies than bone samples.