人脑组织库样本100例质量及影响因素分析

Quality analysis of 100 tissue samples from the postmortem human brain bank

目的检测人脑组织库中保存的脑组织蛋白质、DNA及RNA质量,分析影响其质量的主要因素。方法选取中国医学科学院北京协和医学院人脑组织库保存的100例全脑组织样本,提取蛋白质、DNA及RNA,测定其浓度及吸光度,电泳检测完整性,用Western blotting及Rael-time PCR分别检测。根据不同年龄、死亡原因、取材延迟时间以及样本保存时间进行分组,统计学分析影响脑组织质量的因素。结果人脑组织库中大部分脑组织的DNA、RNA和蛋白质质量保存完好,不同年龄、死亡原因对其质量无显著影响。取材延迟时间超过24h者,其蛋白质浓度及RNA浓度及质量有显著下降。样本保存时间对蛋白质及DNA质量无显著影响,但保存1年以上可能对RNA浓度有影响。结论进行RNA相关分析的人脑组织标本取材延迟时间最好控制在8 h之内,-80℃环境下保存1年之内为佳。而DNA和蛋白质相关分析的时间可以适当延长。

Objective To perform quality analysis for the brain tissue samples from the postmortem Human Brain Bank in Chinese Academy of Medical Sciences and Peking Union Medical College. Methods DNA,RNA and protein were extracted from a total of 100 deep-frozen tissue samples stored in the brain bank,followed by absorption photometry,electrophoresis,Western blotting,RT-PCR and Real-time PCR analysis. The samples were grouped according to age,cause of death,post-mortem delay time and duration of storage. Results The concentrations of DNA,RNA and protein and the integrity of DNA and RNA（ accessed via A260 /280） were compared among groups. The results indicated that there were no major DNA,RNA and protein degradation in the brain tissue with postmortem delay less than 24 hours,and the concentrations were not affected by age and cause of death. In the samples with post-mortem delay over 24 hours,the concentration of protein and RNA as well as the RNA integrity declined significantly. Protein and DNA integrity were not affected by the time of storage,while RNA concentration decreased when the storage time was over 1 year. Conclusion The post-mortem delay should be controlled within 8 hours for RNA analysis,but may be up to 24 hours for protein analysis and even longer for DNA. The human brain tissue can be preserved below-80℃ for as long as 1 year without affecting the sample quality.