Department of Biology, University of Waterloo, Waterloo, ON, Canada.
Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, British Columbia, Canada.
J Virol Methods. 2018 Mar;253:31-37. doi: 10.1016/j.jviromet.2017.12.007. Epub 2017 Dec 26.
RNAlater is a commonly used transport and storage solution for samples collected for fish health investigations, particularly those potentially involving viruses. However, the infectivity of fish viruses after storage in RNAlater have not been determined. Nevertheless, knowledge of pathogen infectivity of preserved samples is crucial for ensuring safe transport and storage protocols. Therefore, the infectivity of three fish RNA viruses in RNAlater was examined at four temperatures: -80 °C, 4 °C, room temperature (RT, approximately 22 °C) and 37 °C. The viruses were viral hemorrhagic septicemia virus (VHSV), infectious pancreatic necrosis virus (IPNV) and chum salmon reovirus (CSV). Overall, three consistent outcomes were observed. First, all three viruses remained infectious in RNAlater at RT or lower. High log titres of these viruses remained over 30 d of storage in either RNAlater or PBS. Second, RNAlater delayed the thermal inactivation of these viruses when compared to PBS at 37 °C. For VHSV, the titre remained high in RNAlater after one day of incubation at 37 °C, but was inactivated to below threshold in PBS over the same period. For IPNV, the titre remained high in RNAlater after 30 d of incubation at 37 °C, but was inactivated to below threshold in PBS over the same period. For CSV, the titre was slightly higher in RNAlater than PBS at 37 °C over 7 d, and by day 30, only samples stored in RNAlater proved infectious at titres above the detection threshold. Third, RNAlater delayed the inactivation of these viruses when they were stored together with head kidney homogenates. For VHSV, infectious virus was recovered from samples stored at 4 °C in RNAlater by day 7 of incubation, whereas it was inactivated to below threshold in PBS over the same period. For both IPNV and CSV, infectious virus was recovered from samples stored at 37 °C in RNAlater for 7 d, but not so in PBS. In summary, fish viruses can remain infectious and are even temporarily protected from inactivation while in RNAlater. This makes RNAlater a potentially useful solution for the transport of fish viruses. At the same time, precautionary measures must be taken when transporting potentially infectious samples in RNAlater.
Rnalater 是一种常用于鱼类健康研究样本采集的运输和储存溶液，特别是那些可能涉及病毒的样本。然而，储存于 Rnalater 中的鱼类病毒的感染力尚未确定。尽管如此，了解保存样本中病原体的感染力对于确保安全的运输和储存方案至关重要。因此，本研究在四个温度下（-80°C、4°C、室温（约 22°C）和 37°C）检测了三种鱼类 RNA 病毒（病毒性出血性败血症病毒 VHSV、传染性胰腺坏死病毒 IPNV 和虹鳟鱼呼肠孤病毒 CSV）在 Rnalater 中的感染力。总的来说，观察到了三个一致的结果。首先，在 RT 或更低温度下，三种病毒在 Rnalater 中均保持感染性。在 Rnalater 或 PBS 中储存 30 天以上，这些病毒的高对数滴度仍保持不变。其次，与 PBS 相比，Rnalater 在 37°C 时可延迟这些病毒的热失活。对于 VHSV，在 37°C 孵育一天后，Rnalater 中的病毒滴度仍很高，但在相同时间内 PBS 中的病毒滴度失活至低于检测阈值。对于 IPNV，在 37°C 孵育 30 天后，Rnalater 中的病毒滴度仍很高，但在相同时间内 PBS 中的病毒滴度失活至低于检测阈值。对于 CSV，在 37°C 下，Rnalater 中的病毒滴度在 7 天内略高于 PBS，到第 30 天，只有储存在 Rnalater 中的样本在滴度高于检测阈值时才具有感染力。第三，当与头肾匀浆一起储存时，Rnalater 可延迟这些病毒的失活。对于 VHSV，在 4°C 孵育 7 天的 Rnalater 储存样本中可回收感染性病毒，而在相同时间内 PBS 中的病毒滴度失活至低于检测阈值。对于 IPNV 和 CSV，在 37°C 孵育 7 天的 Rnalater 储存样本中可回收感染性病毒，但在 PBS 中则不行。总之，鱼类病毒在 Rnalater 中可保持感染性，甚至暂时免受失活的影响。这使得 Rnalater 成为一种用于运输鱼类病毒的潜在有用的解决方案。与此同时，在 Rnalater 中运输潜在传染性样本时必须采取预防措施。
