10个STR基因座荧光复合扩增体系的研制

目的建立10个STR基因座荧光标记复合扩增体系,并评价其法医学应用价值。方法在北京、山西、广东汉族,辽宁满族、西藏藏族群体中调查STR基因座遗传多态性,筛选出9个具有高度多态性和法医应用价值的STR基因座及性别基因座。构建四色荧光素标记复合扩增体系,制备等位基因分型标准物,编制分析软件,并对体系的种属特异性、灵敏度、稳定性、混合样本等检测能力进行考察。结果建立的复合扩增体系遗传稳定好,累积非父排除率可达0.999 96,累积个体识别率可达0.999 999 999 999 3;与CODIS系统均不存在连锁遗传;各基因座间布局合理、无杂峰、扩增结果清晰易辨,并可实现检测分析自动化。体系种属特异性较好,灵敏度为0.1ng,稳定性好,混合样本检出范围在2∶8～8∶2之间。实际案例检材检测结果好。结论本文建立的复合扩增体系在法医学实践中有较好的应用价值。

Development of a 10-locus STR fluorescent-multiplex system for forensic purposes

Objective To establish a new 10-locus STR fluorescent-multiplex system and evaluate its forensic application value.Methods 9 non-CODIS STRs were selected in accordance with the standards based on a survey of 5 ethnic groups in Beijing,Shanxi,Guangzhou,Xiuyan,and Tibet areas.With primers labeled by four color fluorescent dyes(FAM,HEX,TAMRA and ROX),a 10-losus multiplex amplification systems was established.The alleles were named according to the number of repeats,the allelic ladders were constructed,and the software Panel and Bin were developed to analyze the data.Then the species specificity,sensitivity,stability and detection ability for mixed samples of the established system were evaluated.Results The system was of good genetic stability and independence to CODIS loci.The cumulative probability of exclusion(CPE) and the cumulative power of discrimination(CPD) reached to 0.999 96 and 0.999 999 999 999 3 respectively.The genotyping peaks of amplified products were quite distinct,which could be tested and analyzed automatically.Validation studies showed that the system was of high sensitivity of 0.1ng,well species specificity,and good testing results of mixed samples from 2∶ 8 to 8∶ 2.Conclusion The multiplex amplification system established by this study owns high application value in human identification and kinship analysis.