Figure 2

Validation and limit of detection (LoD) of robotic MAVRICS protocol. (A) Manual and robotic extraction were done using the same stock of input samples [1 × 10³ to 1 × 10⁷ RNA copies/input sample] and analyzed by the 2019-nCoV nCoV_N1 and nCoV_N2 RT-qPCR assays. No significant difference was found (Student’s t-test). (B) Three independent robotic RNA extractions of samples with various RNA copy numbers were completed, and the presence of nCoV_N1 and nCoV_N2 targets were determined by RT-qPCR. The slope (mean ± SD), qPCR efficiency (mean ± SD), and correlation coefficient (r²) were calculated. (C) In two independent experiments, TRIzol was added to a saliva sample that was then plated randomly in 24 (assay 1) or 56 (assays 2) wells in the input plate, followed by robotic extraction and RT-qPCR analysis of RNase P. (D, E) To determine the Limit of Detection (LoD) RNA was extracted using the robotic MAVRICS protocol from contrived SARS-CoV-2 samples [100 to 1, 000 RNA copies/input sample], and one step RT-qPCR was performed with the in-house kit R3T qRT-PCR and the probes nCoV_N1, and nCoV_N2. D. Ct values and E. Black bars represent the percentage of detection of nCoV_N1 (left) and nCoV-N2 (right) in replicates of different concentrations.