Oh, look! Supported by Chan Zuckerberg Initiative

Early in the SARS-CoV-2 pandemic, we did not have a readily available source of SARSCoV-2 viral RNA control material or positive patient specimens. For a positive control, we initially

used in vitro transcribed (IVT) RNA from the full-length SARS-CoV-2 N gene (GenBank

accession: MN908947.2), the region targeted by the CDC assay (gifted from Sherlock

Biosciences). We stored 50 µL aliquots of the 1 nM IVT RNA in single-use aliquots at -80 ºC to

avoid RNA degradation from multiple freeze-thaw cycles. If RNA is unavailable, a DNA synthetic

positive control is a possible alternative. Our negative control was pooled negative sample matrix,

comprised of nasopharyngeal specimens collected a year prior to the emergence of SARS-CoV-2,

which was carried through the extraction and amplification process. This negative control also

served as an extraction control in lieu of positive patient specimens. Once positive patient

specimens became available, we developed a new extraction control comprised of a high-titer

patient specimen that we diluted into a large volume of pooled negative sample matrix and froze

in aliquots for storage at -80 ºC

https://www.medrxiv.org/content/10.1101/2020.08.26.20157297v1