DNA提取方法和PCR循环次数对STR扩增成功率的影响

Influence of DNA extraction method and PCR cycle number on STR analysis

目的探讨常见载体上的微量血痕DNA的提取方法、PCR循环次数对STR扩增成功率的影响。方法分别应用Chelex-100法及Chelex-100结合纯化法对8种载体上不同大小的血痕样本进行DNA提取,并采用28次、30次及34次PCR循环进行STR扩增,分别观察其扩增成功率。结果经28次、30次及34次PCR循环,Chelex-100法提取DNA后的STR扩增成功率分别为0.2917,0.3333,0.4583,Chelex-100结合纯化法的STR扩增成功率分别为0.3750,0.4583,0.8750。结论用Chelex-100结合纯化法提取DNA,用34次循环扩增可提高STR基因座的检测成功率。

Objective To study the influence of different DNA extraction methods combined different PCR cycle numbers on STR analysis from trace bloodstain on various carrier often seen in forensic area. Methods Using Chelex-100 and Chelex-100 combine with DNA purification, followed by amplified with Profiler Plus at 28,30 and 34 PCR cycles respectively. Results Success ratios of STR analysis with Chelex-100 DNA extraction method is 0.2917,0.3333 and 0.4583 respectively,while Chelex-100 combined with purification method is 0.3750,0.4583 and 0.8750 respectively. Conclusion Chelex-100 combined with purification DNA extraction method while amplified with 34 cycles can increase the success ratios of STR analysis with trace bloodstain.