基于multi-SNP标记及不拆分策略的复杂混合样本身份溯源研究

对犯罪现场的混合样本进行有效的DNA检验有助于充分挖掘生物检材的证据价值，明确案件的侦查方向和夯实证据固定效力，在司法实践中具有重大的现实需求，在学术研究中已成为了亟待解决的科学问题。在过去的十多年中，研究人员针对混合样本的采集、检测和分析进行了相关研究，在两人混合样本的身份溯源方面取得了一定成效，但是，现有技术对于复杂混合样本的检验和分析效率仍不够理想。课题组在导航实验中发现了一种基于SNP的遗传标记（multi-SNP）在混合样本分析中具有较大应用价值，能够准确鉴别2-3人混合样本。本研究拟充分利用已有研究基础，在人类全基因组上进一步挖掘中国人群中适用于混合样本研究的multi-SNP遗传标记，建立相应的数据库，构建有效的高通量检测体系，并基于数据不拆分的分析策略确认复杂混合样本中贡献者数目及身份信息，为复杂混合样本的身份甄别提供新的检测及分析手段，为法治中国提供坚实技术支撑。

Effective DNA testing of mixtures at the crime scene is helpful to fully excavate the evidentiary value of biological specimens, clarify the investigation direction of the case, and consolidate the effect of evidence. It has significant practical needs in judicial practice and has become a scientific question that is in great need of answering. In the past ten years, researchers have conducted related research on the collection, detection and analysis of mixtures, and have achieved certain results in the identity tracing of two people's mixed samples. However, the existing technology is still not ideal in testing and analyzing complex mixtures. In pilot experiments, we found that a SNP-based genetic marker of multi-SNP has great application value in the analysis of mixtures, and could accurately identify mixed samples of 2 to 3 people. This study intends to further mine the multi-SNP genetic markers on the entire human genome which suitable for mixture research, establish a related database, construct an effective high-throughput detection system, and establish a non-separating data analysis strategy to confirm the number of contributors and identity information in complex mixtures, thus to provide a solid technical support for the rule of law in China.