染色体、阈值—高分辨比较基因组杂交技术的质控关键

Chromosomes and Intervals-The Quality Control of HR-CGH

目的讨论高分辨比较基因组杂交(high resolution comparative genomic hybridization,HR-CGH)技术中高分辨染色体玻片的质量以及不同阈值分析方法对HR-CGH技术的结果影响。方法以正常男性外周血为材料,制备高分辨染色体玻片,分析滴片方案、后固定、预变性等技术环节对染色体玻片质量的影响,从而确立HR-CGH的染色体玻片制备及挑选标准。另以10名正常男、女性外周血为材料,进行HR-CGH检测,杂交结果分别以固定阈值及动态参考阈值(dynamic standard reference intervals,DSRI)进行判定,讨论不同判定方法对HR-CGH检测结果的影响。结果实验证实,过火、后固定及预变性的实施有利于稳定制备高质量的染色体玻片。另外10名正常人标本的杂交结果,以固定阈值法分析的结果均与核型分析结果一致;以ASI软件附带的DSRI法分析,9例结果与核型一致,1例女性结果出现假阳性,为46,XX,dup(15)(q2.2～2.6)。结论高分辨染色体玻片的背景、染色体分散度、抗变性能力是HR-CGH实验成功的关键。以固定阈值分析结果,不受人群差异限制,可在各实验室间广泛应用。而以DSRI分析结果,则受人群差异限制,该DSRI数据必须来自本地正常人群。

Objective To explore the the important influence factor of HR-CGH:chromosomes and intervals. Methods Use normal male peripheral blood to make high resolution chromosomes,to establish the criterion of making and selecting chromosomes by analyzing the influence of drop method,post-fixation and pre-denaturing. In addition,ten HR-CGH experiments were done and analyzed using both fixed threshold and dynamic standard reference intervals. Results The results of the HR-CGH experiments using fixed threshold were the same as their karyotype results while a false positive result 46,XX,dup(15)(q2.2-2.6) was appeared using DSRI. Conclusion The background and the spread of chromrsomes as well as their anti-denatured ability were the key points of HR-CGH experiment. Unlike DSRI,Fixed threshold could be used in all labs without the limitation of population.