Barretos Cancer Hospital Biobank, Barretos, Brazil.
Department of Pathology, Barretos Cancer Hospital, Barretos, Brazil.
Biopreserv Biobank. 2023 Feb;21(1):74-80. doi: 10.1089/bio.2021.0131. Epub 2022 May 25.
Biobanks process, store, and supply biological materials for research. Preanalytical factors, especially storage time and temperature, must be controlled and standardized at all stages when handling biospecimen samples, especially because the literature reports highly contradictory optimal parameters. As large-sample studies are required to better understand the influence of time and temperature on cryopreserved samples' quality for genomic research, this study evaluated the integrity and quality of cryopreserved samples stored for up to 9 years at the biobank of Barretos Cancer Hospital, one of the largest biobanks in Latin America. We randomly selected 447 samples with tumor tissue paired with buffy coat or peripheral blood mononuclear cells (PBMCs) that were stored from 2008 to 2016. The genetic material quality was evaluated based on RNA integrity (RIN) and DNA integrity (DIN) ≥7, which indicated undegraded samples, and compared with storage time, which means that for DNA storage time, samples <8.1 and ≥8.1 years and for RNA <4.5 and ≥4.5 were used. A total of 190 tumor tissues were eligible for DNA and RNA extraction. Those stored for 8 years had lower DIN (68%) than those stored for a shorter period (92%). A similar pattern, based on storage time (<8.1 and ≥8.1 years), was observed in the buffy coat (74% and 95%, respectively) and PBMCs (54% and 96%, respectively). For RNA extracted from tumor tissues, we observed lower RIN in samples stored for 4.5 years (17%) than in samples stored for a shorter period (45%). Buffy coat and PBMC samples stored at -30°C exhibited greater degradation (26%) than those stored at -80°C (1%). The DIN ( = 0.15) and RNA ( = 0.18) were unrelated to topography type. The temperature, particularly cryopreservation methodology, and storage time were the main factors that affected nucleic acid integrity, especially RNA, during cryopreservation of biospecimens.
生物银行处理、存储和提供用于研究的生物材料。在处理生物样本时，必须控制和标准化所有阶段的预分析因素，特别是储存时间和温度，特别是因为文献报告了高度矛盾的最佳参数。由于需要进行大型样本研究，才能更好地了解时间和温度对基因组研究中冷冻保存样本质量的影响，因此本研究评估了储存长达 9 年的冷冻样本的完整性和质量，这些样本来自拉丁美洲最大的生物银行之一——巴雷托斯癌症医院的生物银行。我们随机选择了 447 个肿瘤组织样本，这些样本与白细胞或外周血单核细胞（PBMC）配对，从 2008 年到 2016 年进行了储存。基于 RNA 完整性（RIN）和 DNA 完整性（DIN）≥7 评估遗传物质质量，这表明未降解的样本，并与储存时间进行比较，即对于 DNA 储存时间，使用 <8.1 年和≥8.1 年的样本，对于 RNA 使用 <4.5 年和≥4.5 年的样本。共有 190 个肿瘤组织样本适合进行 DNA 和 RNA 提取。储存 8 年的样本的 DIN（68%）低于储存时间较短的样本（92%）。在白细胞和 PBMC 中也观察到类似的模式（分别为 74%和 95%，54%和 96%），这取决于储存时间（<8.1 年和≥8.1 年）。对于从肿瘤组织中提取的 RNA，我们观察到储存 4.5 年的样本的 RIN（17%）低于储存时间较短的样本（45%）。-30°C 储存的白细胞和 PBMC 样本的降解程度（26%）高于-80°C 储存的样本（1%）。DIN（=0.15）和 RNA（=0.18）与地形类型无关。温度，特别是冷冻保存方法和储存时间，是影响生物样本冷冻保存期间核酸完整性的主要因素，特别是 RNA。
