基于8色荧光标记的Multi-InDel复合检测体系在降解混合检材鉴定的应用研究

降解混合检材的DNA分型是法医实际工作中面临的难题和重大挑战。多重插入缺失遗传标记（Multi-InDel）具有多态性高、扩增片段短、无stutter峰等特点，并且兼容毛细管电泳平台，是研究降解混合检材的理想遗传标记。本课题拟通过生物信息学方法从千人基因组数据库中筛选扩增片段不超过125bp的Multi-InDel基因座，结合群体数据进一步甄选多态性高的基因座；建立基于8色荧光标记的Multi-InDel复合体系，完成体系优化并进行稳健性、有效性和可靠性验证；检测人工降解混合检材，评估复合体系在降解混合检材鉴定中的系统效能，建立基于完全连续似然率法的Multi-InDel混合分型结果解析方案并应用于法医实际案件中。本项目的完成将为降解混合案件检材的法医学分析提供理论支持和可推广使用的新方法。

DNA genotyping from degraded mixtures is a difficult problem and major challenge for forensic science. Multi-InDel has the characteristics of high polymorphisms, short amplified fragments, no stutter peaks and could be detected on capillary electrophoresis platform, making it an ideal genetic marker for degraded mixtures analysis. This study intends to select a number of Multi-Indel loci with short Amplicons (< 125 bp) from public databases by bioinformatics methods, further screen high polymorphic loci through population data; establish a Multi-InDel detection system based on 8-dye fluorescent labeled technology and verify the robustness, effectiveness and reliability of this system; detect artificially degraded mixtures, develop a mixture analysis method based on continuous likelihood rate method and applied in forensic caseworks. This project will provide a new method that can be promoted and used for the forensic analysis of degraded mixtures.