Long-Term Preservation of SARS-CoV-2 RNA in Silk for Downstream RT-PCR Tests.
Anal Chem
; 94(10): 4522-4530, 2022 03 15.
Article
in English
| MEDLINE | ID: covidwho-1721381
ABSTRACT
Positive controls made of viral gene components are essential to validate the performance of diagnostic assays for pathogens like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, most of them are target-specific, limiting their application spectrum when validating assays beyond their specified targets. The use of an inactivated whole-virus RNA reference standard could be ideal, but RNA is a labile molecule that needs cold chain storage and transportation to preserve its integrity and activity. The cold chain process stretches the already dwindling storage capacities, incurs huge costs, and limits the distribution of reference materials to low-resource settings. To circumvent these issues, we developed an inactivated whole-virus SARS-CoV-2 RNA reference standard and studied its stability in silk fibroin matrices, i.e., silk solution (SS) and silk film (SF). Compared to preservation in nuclease-free water (ddH2O) and SS, SF was more stable and could preserve the SARS-CoV-2 RNA reference standard at room temperature for over 21 weeks (â¼6 months) as determined by reverse transcription polymerase chain reaction (RT-PCR). The preserved RNA reference standard in SF was able to assess the limits of detection of four commercial SARS-CoV-2 RT-PCR assays. In addition, SF is compatible with RT-PCR reactions and can be used to preserve a reaction-ready primer and probe mix for RT-PCR at ambient temperatures without affecting their activity. Taken together, these results offer extensive flexibility and a simpler mechanism of preserving RNA reference materials for a long time at ambient temperatures of ≥25 °C, with the possibility of eliminating cold chains during storage and transportation.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
RNA, Viral
/
COVID-19
Type of study:
Diagnostic study
/
Prognostic study
Topics:
Long Covid
Limits:
Humans
Language:
English
Journal:
Anal Chem
Year:
2022
Document Type:
Article
Affiliation country:
Acs.analchem.2c00169
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