Fig. 6.

Copy number quantification of control materials using dPCR. (A) Correlation between copy number estimates obtained by RT-dPCR and Cq values obtained by RT-qPCR using two SARS-CoV-2 targets. Three point dilution series of the IVT The RT-dPCR copy numbers were log2 transformed and plotted against the Cq Values for the CDC N1 (blue diamonds) and CDC N2 (red diamonds) assays. Good correlation was obtained between the two platforms and targets. (B) Quantification of control material synthesised by multiple IVT molecules to cover the whole viral genome. Three separate orders from the same manufacturers batch and three different manufacturers batches where measured by RT-dPCR using the CDC N2 (red diamonds) and Sarbeco E (green diamonds) assays. Data is presented as a percentage of the assigned manufacturers concentration. All materials analysed were significantly lower than the assigned value, and by as much as 90% lower. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)