短串联重复序列基因座在石蜡包埋组织中的应用

摘要

Objective To study the difference of the short tandem repeats (STR) loci genotyping in paraffin embedded tissue by using three kits .Methods DNA were extracted from intestinal tumor in paraffin‐embedded tis‐sue which was preservd for a month by using Qiagen method ,fluorescent multiplex PCR by using identifiler kit ,Pow‐erPlex 21 kit and Investigator HDplex kit ,capillary electrophoresis and fragment analysis technique were used to de‐tect STR loci .Comparing the recalling rations of STR loci of three kits and the genotype of the homologous normal samples which include paraffin embedded tissue ,blood ,hair and oral swab .Results DNA concentration extracted from paraffin‐embedded tissue were detected between 6-85 ng/μL ,OD=1 .7 -2 .2 .when DNA concentration >15 ng/μL ,the full STR loci genotype was detected by identifiler kit ,and when DNA concentration was 85 ng/μL ,the full STR loci genotype was detected by PowerPlex 21 kit ,however ,there was no full peaks of all the STR loci by using HDplex kit .There were several different STR loci genotype between paraffin embedded tissue and other homologous normal samples .There were allelic imbalance and drop‐outs in D6S474 ,D4S2366 and D21S2055 .Conclusion The concentration and purity of DNA extracted from paraffin embedded tissue were the important influential factors for STR loci genotype .The phenomenon of missing genetic information was related to sample properties and the detec‐ting system .There was high practical value for STR loci genotyping in paraffin embedded tissue by using identifiler kit .%目的：探讨3种STR基因座分型系统在石蜡包埋组织基因座分型的差异。方法采用Qiagen法对保存1个月的石蜡包埋组织进行DNA提取，用Identifiler系统、PowerPlex 21系统及Investigator HDplex 系统对STR基因座进行聚合酶链反应复合扩增、毛细管电泳、荧光检测及片段分析，比较3种系统的STR基因座检出率，并且采集组织同一个体的血液、毛发、口腔拭子等样本进行STR基因座分型，比较同一个体不同器官组织STR基因座分型的差异。结果经紫外分光光度计测定石蜡包埋组织的DNA浓度为6～85 ng／μL ，纯度1．7～2．2，Iden‐tifiler系统能够在DNA浓度大于15 ng／μL时得到完整的基因座分型，PowerPlex 21系统在DNA浓度为85 ng／μL时得到完整的基因座分型，而HDplex系统在石蜡组织检测中均未获得完整的基因座分型。石蜡包埋组织与其他器官组织分型结果存在差异，其中D6S474、D4S2366和D21S2055基因座存在等位基因不平衡或基因座丢失现象。结论石蜡包埋组织中DNA的浓度和纯度是STR基因座分型的重要影响因素，遗传信息丢失现象与检验对象的性状有关，也与所采用的检测系统有关，Identifiler系统对石蜡包埋组织的STR基因座分型具有较高的实用价值。