免疫磁珠法分离混合样本中血液成分的探究  

Isolation of blood components from exfoliated epithelial cells by immunomagnetic beads

作　　者：吴先宇 薛建[2] 买亚茹 王颖希 李倩[1] 焦章平[2] Wu Xianyu;Xue Jian;Mai Yaru;Wang Yingxi;Li Qian;Jiao Zhangping(Shanxi Medical University,Jinzhong 030600;Criminal InvestigationCorps of Beijing Public Security Bureau,Beijing 100192)

机构地区：[1]山西医科大学,山西晋中030600 [2]北京市公安局刑事侦查总队,北京100192

出　　处：《中国法医学杂志》2023年第1期35-38,共4页Chinese Journal of Forensic Medicine

摘　　要：目的基于免疫磁珠法分离脱落上皮细胞中的白细胞,消除或减弱混合检材中血液来源STR分型对结果分析的干扰。方法分别取两名不同个体的血液和口腔脱落上皮细胞,按不同比例制备成混合样本作为实验组,并同时制备细胞量相等的对照组。应用免疫磁珠法分离实验组样本中白细胞,并与对照组以相同条件进行DNA提取、扩增、分型,对比两组STR分型结果。结果当血液量较少时,对照组为混合STR分型,经免疫磁珠法分离混合检材中白细胞后,实验组为单一来源STR分型;当血液量较多时,此时对照组为混合STR分型,但口腔脱落上皮细胞来源的STR分型谱带峰高较低甚至丢失,经免疫磁珠法后,实验组仍为STR混合分型,但口腔脱落上皮细胞来源的STR分型谱带成为主峰;当混合样本中口腔脱落上皮细胞微量,血液占比极大时,此时对照组为血液来源的单一STR分型结果,经免疫磁珠法后,实验组为STR混合分型,包含口腔脱落上皮细胞来源的所有等位基因分型。结论该方法可用于分离脱落上皮细胞中血液成分,降低血液来源的DNA比例,能够改善此类混合检材中目的细胞的STR分型结果,为刑事案件中含有血迹浸染的混合生物检材的检验提供了一种新思路。Objective To eliminate or reduce the interference of STR typing of the blood in the mixed samples by removing white blood cells from the exstrated epithelial cells and blood using the immunomagnetic beads.Methods Blood and oral exfoliated epithelial cells of two different individuals were taken and the mixed samples were prepared in different proportions as the experimental group,and the control group with roughly the same cell volume was prepared at the same time.The white blood cells in the samples of the experimental group were removed by the immunomagnetic beads method.Then,the DNA was extracted,amplified and typed under the same conditions with the control group.The improvement of STR maps of the experimental group comparing to the control group was compared and analyzed.Results When the blood volume was small,the control group was mixed STR typing.After the white blood cells were removed from the mixed samples by immunomagnetic beads,the experimental group showed single source STR typing.When the blood volume was large,the control group was mixed STR typing,but the peak of STR typing band from oral exfoliated epithelial cells was low or even lost.After the immunomagnetic bead method,the experimental group was still mixed STR typing,but the STR typing band from oral exfoliated epithelial cells became the main peak.When the mixed sample contained a small amount of oral exfoliated epithelial cells but a large proportion of blood,the control group only showed a single STR typing result derived from blood,while the experimental group was a STR mixed typing result after the immunomagnetic bead method,which included all alleles from oral exfoliated epithelial cells.Conclusion This method can be used to separate blood components from exfoliated epithelial cells,reduce the proportion of DNA from blood,and improve the STR typing result of target cells in such mixed samples.It provides a new idea for the detection of mixed biological samples containing blood stains in criminal cases.

关 键 词：免疫磁珠法 细胞分离 混合斑 STR分型 

分 类 号：D919.2[医药卫生—法医学]