Li Jun, Gao Hongfei, Li Yunjing, Zhai Shanshan, Xiao Fang, Wu Gang, Wu Yuhua
Key Laboratory of Agricultural Genetically Modified Organisms Traceability of the Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China.
Foods. 2024 Feb 28;13(5):747. doi: 10.3390/foods13050747.
The genetically modified (GM) maize DBN9936 with a biosafety certificate will soon undergo commercial application. To monitor the safety of DBN9936 maize, three genomic DNA (gDNA) reference materials (RMs) (DBN9936a, DBN9936b, and DBN9936c) were prepared with nominal copy number ratios of 100%, 3%, and 1% for the DBN9936 event, respectively. DBN9936a was prepared from the leaf tissue gDNA of DBN9936 homozygotes, while DBN9936b and DBN9936c were prepared by the quantitative mixing of gDNA from the leaf tissues of DBN9936 homozygotes and non-GM counterparts. Validated DBN9936/ duplex droplet digital PCR was demonstrated to be an accurate reference method for conducting homogeneity study, stability study, and collaborative characterization. The minimum intake for one measurement was determined to be 2 μL, and the gDNA RMs were stable during transport at 37 °C for 14 days and storage at -20 °C for 18 months. Each gDNA RM was certified for three property values: DBN9936 event copy number concentration, reference gene copy number concentration, and DBN9936/ copy number ratio. The measurement uncertainty of the certified values took the uncertainty components related to possible inhomogeneity, instability, and characterization into account. This batch of gDNA RMs can be used for calibration and quality control when quantifying DBN9936 events.
具有生物安全证书的转基因玉米DBN9936即将进行商业化应用。为监测DBN9936玉米的安全性，制备了三种基因组DNA（gDNA）参考物质（RMs）（DBN9936a、DBN9936b和DBN9936c），其DBN9936事件的标称拷贝数比例分别为100%、3%和1%。DBN9936a由DBN9936纯合子的叶片组织gDNA制备，而DBN9936b和DBN9936c通过将DBN9936纯合子和非转基因对应物的叶片组织gDNA定量混合制备。经验证的DBN9936/双链液滴数字PCR被证明是进行均匀性研究、稳定性研究和协作表征的准确参考方法。确定一次测量的最小进样量为2 μL，gDNA参考物质在37℃运输14天和-20℃储存18个月期间稳定。每个gDNA参考物质针对三个特性值进行了认证：DBN9936事件拷贝数浓度、参考基因拷贝数浓度和DBN9936/拷贝数比例。认证值的测量不确定度考虑了与可能的不均匀性、不稳定性和表征相关的不确定度分量。这批gDNA参考物质可用于在定量DBN9936事件时进行校准和质量控制。
