Grice Marine Laboratory, College of Charleston, Charleston, South Carolina, USA.
Elmhurst College, Elmhurst, Illinois, USA.
Biopreserv Biobank. 2020 Oct;18(5):358-366. doi: 10.1089/bio.2020.0026. Epub 2020 Jun 23.
Sample storage conditions can affect accuracy and reproducibility of biological measurements. Storing samples rapidly at the lowest available temperatures is considered ideal but is not always feasible when sampling in remote and logistically challenging field conditions, as is often the case with sea turtles. The objective of this study was to examine the stability of plasma proteins and quality of whole blood RNA from loggerhead sea turtle samples collected as part of an eighteen-year-long curated specimen collection. These biological variables are often used to assess sea turtle health; therefore, it is necessary to maintain the integrity of these components during storage. Protein electrophoresis was conducted on heparinized plasma from individual turtles collected in 2018 ( = 3), 2008 ( = 3), and 2001 ( = 3). Plasma was also pooled from four turtles sampled in 2018 and subjected to various storage temperatures. Whole blood was collected in blood collection tubes containing sodium heparin or PAXgene tubes with an RNA preservative. These were subjected to different storage treatments that can possibly occur during logistically difficult field sampling. Following various treatments, plasma proteins showed minor differences across collection years and no differences among storage treatments were observed, even when exposed to 38°C for three hours. RNA quality was assessed from whole blood using an RNA integrity number (RIN). RINs were poor from sodium heparin tubes that were frozen and from PAXgene tubes after an extended thaw. High-quality RNA was obtained from sodium heparin tubes that were never frozen and from PAXgene tubes with freezing delayed by up to 11 days. Overall, these results indicate that plasma proteins remain stable over time and when exposed to undesirable storage conditions, and RNA degrades rapidly in sea turtle blood after freezing and when not properly preserved. These aspects are important to consider when planning sampling protocols and logistics for optimal long-term sample preservation.
样本储存条件会影响生物测量的准确性和重现性。尽快将样本储存在最低可用温度下被认为是理想的，但在远程和物流复杂的野外条件下采样时，这并不总是可行的，而海龟通常就是这种情况。本研究的目的是检查从作为十八年长期 curated 标本收集一部分收集的红海龟样本中提取的血浆蛋白稳定性和全血 RNA 的质量。这些生物变量常用于评估海龟的健康状况；因此，在储存过程中必须保持这些成分的完整性。对 2018 年（n=3）、2008 年（n=3）和 2001 年（n=3）采集的单个海龟肝素化血浆进行蛋白质电泳。还从 2018 年采集的四只海龟中采集血浆并将其储存在不同的温度下。将血液采集在含有肝素钠的采血管或含有 RNA 保存剂的 PAXgene 管中。这些都经过了可能在物流困难的野外采样过程中发生的不同储存处理。经过各种处理后，血浆蛋白在采集年份之间显示出微小差异，即使在 38°C 下暴露三个小时，也没有观察到储存处理之间的差异。使用 RNA 完整性数（RIN）评估全血中的 RNA 质量。冷冻的肝素钠管和解冻时间延长的 PAXgene 管的 RIN 很差。从未冷冻的肝素钠管和冷冻延迟多达 11 天的 PAXgene 管中获得了高质量的 RNA。总体而言，这些结果表明，血浆蛋白随时间推移保持稳定，并且在暴露于不理想的储存条件下保持稳定，并且 RNA 在冷冻后和未正确保存时在海龟血液中迅速降解。在规划采样方案和物流以实现最佳长期样品保存时，这些方面非常重要。
