The production and characterization of SARS-CoV-2 RNA reference material

SARS-CoV-2 in vitro transcribed RNA reference materials (RM), UME RM 2019 and UME RM 2020, were produced by Scientific and Technological Research Council of Turkey (TUBITAK), National Metrology Institute (UME), to be used as a quality control material for SARS-CoV-2 measurements, in liquid-frozen and lyophilized forms, respectively. These RNA RMs include ten internationally recommended SARS-CoV-2 target gene fragments (Pasteur-RdRp-IP2, Pasteur-RdRp-IP4, Charite-E, Charite-RdRp, CDC-N1, CDC-N2, China CDC-ORF1ab, China CDC-N, Hong Kong-ORF1b, and Hong Kong-N) for virus detection and one human gene fragment (RNase P) as an internal control. Two different platforms, RT-qPCR and RT-ddPCR, were used to characterize UME RM 2019 (UME RM 2020 was only characterized with RT-qPCR). The homogeneity studies were evaluated by RT-qPCR. According to these results, it has been shown that both reference materials are homogeneous for intended use. Short-term studies were also conducted similarly for mimicking transport conditions and UME RM 2020, which is produced in lyophilized form, unlike other reference materials available in the market, provides convenience for users by ensuring that the reference material remains stable for 17 days even at 45 °C temperature. The lyophilized formulation of the reference material had greater stability which would allow it to be shipped without cooling items. The development of such RNA reference materials provides quality control for existing and newly designed RNA-based virus detection tests and it helps the prevention and control of epidemics.