Objectives: To develop a multiplex PCR amplification system (EX20+30Y for short) of 19 autosomes, 30 Y-STR loci plus the gender indicator, and evaluate its forensic application value.
Methods: With the six-color fluorescence labeling technology, a multiplex amplification system of 19 autosomal STR loci and 30 Y-STR loci plus the gender indicator was constructed. Blood samples from 210 unrelated individuals, 69 daily case samples and standard samples 9948 and 9947A were collected for loci detection and analysis. The EX20+30Y multiplex amplification system was evaluated by its sensitivity, mixed sample detection ability, species specificity, balance, direct amplification ability, sample applicability and anti-inhibition ability.
Results: Multiplex amplification of blood samples from 210 unrelated individuals by the detection system obtained accurate genotyping results. The detection sensitivity of standard samples was 0.125 ng and the species specificity was high. The 69 samples from daily cases were genotyped correctly. Moreover, standard sample 9948 could be accurately genotyped even if the samples contained a certain concentration of inhibitors.
Conclusions: The multiplex amplification system established in this study can conduct combined examination of 19 autosomes, 30 Y-STR loci plus the gender indicator with accurate genotyping and high sensitivity. It has a good forensic application prospect.
目的: 构建19个常染色体、30个Y-STR基因座以及性别基因座的复合PCR扩增体系（简称EX20+30Y）并评估其法医学应用价值。方法: 采用六色荧光标记技术，构建19个常染色体STR基因座、30个Y-STR基因座以及性别基因座的复合扩增体系。收集210份无关个体血样、69份日常案件样本、标准品9948和标准品9947A进行基因座检测分析，评估EX20+30Y复合扩增体系的灵敏度、混合样本检测能力、种属特异性、均衡性、直接扩增能力、样本适用性以及抗抑制性。结果: 本检测体系对210份无关个体血样复合扩增分型准确，对标准品检测灵敏度达0.125 ng，种属特异性高，69份案件检材全部准确分型，当标准品9948含一定限度范围的抑制剂时也可获得准确分型。结论: 本研究建立的复合扩增体系可联合检测19个常染色体、30个Y-STR基因座以及性别基因座，分型准确，灵敏度高，具有良好的法医学应用前景。.
Keywords: Y chromosome; autosome; forensic genetics; kit; short tandem repeat.