Ocean Genome Legacy Center, Northeastern University, Nahant, Massachusetts, United States of America.
Brookline, New Hampshire, United States of America.
PLoS One. 2020 Aug 20;15(8):e0237356. doi: 10.1371/journal.pone.0237356. eCollection 2020.
DESS is a formulation widely used to preserve DNA in biological tissue samples. Although it contains three ingredients, dimethyl sulfoxide (DMSO), ethylenediaminetetraacetic acid (EDTA) and sodium chloride (NaCl), it is frequently referred to as a DMSO-based preservative. The effectiveness of DESS has been confirmed for a variety of taxa and tissues, however, to our knowledge, the contributions of each component of DESS to DNA preservation have not been evaluated. To address this question, we stored tissues of three aquatic taxa, Mytilus edulis (blue mussel), Faxonius virilis (virile crayfish) and Alitta virens (clam worm) in DESS, each component of DESS individually and solutions containing all combinations of two components of DESS. After storage at room temperature for intervals ranging from one day to six months, we extracted DNA from each tissue and measured the percentage of high molecular weight (HMW) DNA recovered (%R) and normalized HMW DNA yield (nY). Here, HMW DNA is defined as fragments >10 kb. For comparison, we also measured the %R and nY of HMW DNA from extracts of fresh tissues and those stored in 95% EtOH over the same time intervals. We found that in cases where DESS performed most effectively (yielding ≥ 20%R of HMW DNA), all solutions containing EDTA were as or more effective than DESS. Conversely, in cases where DESS performed more poorly, none of the six DESS-variant storage solutions provided better protection of HMW DNA than DESS. Moreover, for all taxa and storage intervals longer than one day, tissues stored in solutions containing DMSO alone, NaCl alone or DMSO and NaCl in combination resulted in %R and nY of HMW DNA significantly lower than those of fresh tissues. These results indicate that for the taxa, solutions and time intervals examined, only EDTA contributed directly to preservation of high molecular weight DNA.
DESS 是一种广泛用于保存生物组织样本中 DNA 的配方。尽管它包含三种成分，二甲基亚砜（DMSO）、乙二胺四乙酸（EDTA）和氯化钠（NaCl），但它通常被称为基于 DMSO 的防腐剂。DESS 的有效性已在多种分类群和组织中得到证实，然而，据我们所知，DESS 中每个成分对 DNA 保存的贡献尚未得到评估。为了解决这个问题，我们将三种水生分类群的组织（贻贝、螯虾和泥蚶）分别保存在 DESS、DESS 的每个成分以及含有 DESS 两种成分组合的溶液中。在室温下储存一天到六个月的不同时间间隔后，我们从每种组织中提取 DNA，并测量回收的高分子量（HMW）DNA 的百分比（%R）和归一化 HMW DNA 产量（nY）。在这里，高分子量 DNA 定义为片段>10 kb。为了进行比较，我们还测量了在相同时间间隔内新鲜组织和保存在 95% EtOH 中的组织提取物的 HMW DNA 的%R 和 nY。我们发现，在 DESS 表现最佳的情况下（产生≥20%的 HMW DNA），所有含有 EDTA 的溶液都与 DESS 一样有效或更有效。相反，在 DESS 表现较差的情况下，DESS 的六种变体存储溶液都没有提供比 DESS 更好的 HMW DNA 保护。此外，对于所有分类群和储存时间间隔超过一天的情况，单独保存在 DMSO 溶液、NaCl 溶液或 DMSO 和 NaCl 组合溶液中的组织导致 HMW DNA 的%R 和 nY 显著低于新鲜组织。这些结果表明，在所研究的分类群、溶液和时间间隔中，只有 EDTA 直接有助于保存高分子量 DNA。
