Room temperature storage and shipping of encapsulated synthetic RNAs as quality control materials for SARS-CoV-2 molecular diagnostic assays.

The Coronavirus pandemic unveiled the unprecedented need for diagnostic tests to rapidly detect the presence of pathogens in the population. Real-time RT-PCR and other nucleic acid amplification techniques are accurate and sensitive molecular techniques that necessitate quality control strategies and stable quality control materials. To meet this need, Twist Bioscience has developed and released synthetic RNA controls. However, RNA is an inherently unstable molecule needing cold storage, costly shipping, and resource-intensive logistics. Imagene provides a solution to this problem by encapsulating dehydrated RNA inside metallic capsules filled with anhydrous argon, allowing room temperature and eco-friendly storage and shipping. This technology initially developed for DNA storage has been successfully applied to RNA and other biospecimen and extensively validated through real time and accelerated aging. Here, RNA controls produced by Twist Bioscience were encapsulated in RNAshells and distributed to several laboratories that used them for COVID-19 detection tests by amplification. One RT-LAMP procedure, four different RT-PCR devices and 6 different PCR kits were used. The amplification targets were genes E, N; RdRp, Sarbeco-E and Orf1a/b. RNA retrieval was satisfactory, and the detection was reproducible. RNA stability was checked by real-time (3 years at room temperature) and accelerated aging (16 h at 90 °C, corresponding to approximately 10 years of storage at 25 °C, according to our previously published Arrhenius study for encapsulated RNA). The results were not significantly different from those for unaged capsules. This room temperature RNA stability allows the preparation and distribution of large strategic batches which can be stored for more than 10 years a long time and used for standardization processes between detection sites. Moreover, this provides the advantage of single-use and field usability across varying temperatures. Consequently, this type of encapsulated synthetic RNA, processed at room temperature, can be used as internal quality control materials for the SARS-Cov-2 virus as well as for detection of other RNA viruses.