水浸和洗涤血样本的DNA检验

DNA examination of diluted or washed blood samples

目的对经水作用的血样本DNA分型检验结果进行分析探讨。方法全血样本分为两组,水稀释组用水将全血样本稀释5、10、20、25、30倍后制作血斑;洗涤组分为纯水手洗、肥皂弱洗、肥皂强洗、84消毒液浸洗和洗衣粉机洗等5种洗涤方式。所有样本用IQ试剂盒提取DNA,Identifiler PlusTM试剂盒扩增,并进行分型检测。结果血液稀释组中心部位检材,均无等位基因丢失,除30倍稀释样本外,峰高均衡性均大于70%;外周部位检材出现2～10个等位基因丢失,峰高均衡性均小于50%。洗涤组中除84消毒液洗涤样本未检出DNA谱带外,其余均无等位基因丢失,而峰高及均衡性以手洗和肥皂弱洗样本更好。结论经水稀释或洗涤剂清洗的血样本,即使联苯胺预实验结果为阴性,选取合适的检验部位,仍可获得DNA分型。

Objective To discuss the DNA genotyping results of blood samples interacted with water. Methods Blood samples were divided into two groups： dilution group where the blood samples were diluted 5, 10,20,25,30 times with water and washing group where the blood stains were washed with hands by water, soap, 84 disinfector or washed by washing machine. DNA was extracted by IQ kit and amplified by Identifiler PlusTM kit. Results In the center part of the dilution group samples there was no allele loss and the peak high balance was above 70% except 30-fold diluted blood samples; 2 - 10 allele were lost and the peak high balance was less than 50% in the peripheral part. There was no allele loss in the washing group except the 84 disinfector washed samples. Peak height and balance were much better in the samples washed with hands by water and soap for 2 minutes. Conclusion DNA STR results could be obtained from diluted or washed blood samples although Benzidine test was negative in some cases. It is important to target right part of the blood sample to be exambined.