Goudoudaki Stavroula, Kambouris Manousos E, Manoussopoulou Marianna, Patrinos George P, Velegraki Aristea, Manoussopoulos Yiannis
Plant Protection Division of Patras, ELGO-Demeter, Patras, Greece.
Department of Pharmacy, University of Patras, Patras, Greece.
Bio Protoc. 2023 Sep 5;13(17):e4796. doi: 10.21769/BioProtoc.4796.
In the field of molecular genetics, DNA extraction protocols and kits are sample-specific and proprietary, preventing lateral distribution among similar facilities from different sectors to alleviate supply shortages during a crisis. Expanding upon previous fast extraction protocols such as alkaline- and detergent-based ones, the use of boiling-hot water to rupture cells, virions, and nuclei, as proposed during the COVID-19 pandemic, might alleviate shortages and costs. Different soft, relatively abundant (highly enriched), and uncomplicated (genomically homogenous and with few inhibitors) biosamples are collected in 1.5 mL tubes, mixed with boiling-hot water, and stirred vigorously, so as to have membranes lysed and proteins deactivated; mechanical disruption may be used as well if necessary. Incubation in boiling water bath for 20-30 min follows. Depending on sample type and quantity, which affects the total extraction volume, 2-5 μL are pipetted off for direct PCR and the same volume for two decimal serial dilutions. The latter are intended to optimize the crude extract to a workable DNA/inhibitor concentration balance for direct PCR. Uncomplicated, highly enriched samples such as mycelial growth in fruits and human swab samples can be processed, contrary to complicated samples such as blood and physically unyielding samples such as plant tissue. The extract can be used for immediate PCR in both benchtop and portable thermocyclers, thus allowing nucleic acid amplification tests (NAAT) being performed in resource-limited settings with low cost and waste footprint or during prolonged crises, where supply chain failures may occur. Key features DNA extraction from different sample types using only boiling water and occasional mechanical assistance. Crude extract serially diluted twice, 10- and 100-fold, to bypass purification and quantification steps. Direct PCR for 2-10 μL of crude lysate and dilutions (conditional to sample type and quantity) to enhance probability of workable DNA-inhibitors' concentrations. Lowers the cost and curtails the overall footprint of testing to increase sustainability in field operations and in standard lab environments under supply chain derailment.
在分子遗传学领域,DNA提取方案和试剂盒是针对特定样本的且具有专有性,这使得不同部门的类似机构之间无法横向调配,以缓解危机期间的供应短缺。在之前基于碱性和洗涤剂的快速提取方案基础上,如在新冠疫情期间所提议的,使用沸水来裂解细胞、病毒粒子和细胞核,可能会缓解短缺并降低成本。将不同的柔软、相对丰富(高度富集)且简单(基因组均一且抑制剂少)的生物样本收集到1.5毫升试管中,与沸水混合并剧烈搅拌,以使细胞膜裂解、蛋白质失活;如有必要,也可使用机械破碎。随后在沸水浴中孵育20 - 30分钟。根据样本类型和数量(这会影响总提取体积),吸取2 - 5微升用于直接PCR,并吸取相同体积用于进行两次十进制系列稀释。后者旨在将粗提物优化到适合直接PCR的可行DNA/抑制剂浓度平衡。与血液等复杂样本以及植物组织等物理上难以处理的样本不同,像水果中的菌丝体生长和人类拭子样本这样简单、高度富集的样本可以进行处理。提取物可立即用于台式和便携式热循环仪中的PCR,从而能够在资源有限的环境中以低成本和低废弃物足迹进行核酸扩增检测(NAAT)操作,或者在可能出现供应链故障的长期危机期间进行检测。关键特性:仅使用沸水和偶尔的机械辅助从不同样本类型中提取DNA。粗提物进行两次连续稀释,分别为10倍和100倍,以绕过纯化和定量步骤。对2 - 10微升粗裂解物及其稀释液进行直接PCR(取决于样本类型和数量),以提高可行的DNA - 抑制剂浓度的概率。降低成本并减少检测的总体足迹,以提高野外作业以及供应链中断情况下标准实验室环境中的可持续性。