"""SARS-CoV-2 RNA can be detected from COVID-19 patient nasopharyngeal swabs by RT-qPCR without an RNA extraction step ( a ) Nasopharyngeal (NP) swab diluents from two confirmed COVID-19 patients were pooled, and using the 2019-nCoV_N3 primer/probe set, the mixture was either i) subjected to RNA extraction using the Qiagen QIAamp Viral RNA Mini kit followed by subsequent testing by RT-qPCR (using the equivalent of 11.3 ul swab diluent) or ii) directly added to the RT-qPCR reaction, with or without a preheating step (five minutes at 70°C, """"NP sample + heat""""). As a control, the indicated quantities of the CDC 2019-nCoV Positive Control SARS-CoV-2 synthetic RNA was spiked into M6 transport media, purified using the QIAamp Viral RNA Mini kit, and screened by RT-qPCR. NP swab samples from seven additional donors were screened by direct RT-qPCR for SARS-CoV-2 RNA using ( b ) the 2019-nCoV_N1 primer/probe set, ( c ) the 2019-nCoV_N2 primer/probe set, or ( d ) for human RNase P RNA using the RP primer probe set. NP swab samples from donors 1 – 4 were previously shown to contain SARS-CoV-2 RNA by standard clinical RT-qPCR, while donors 5 – 7 were negative. For each primer/probe set, 7 µL ( a ) or 3 µL ( b, c, d ) of NP swab diluent was tested in the RT-qPCR reaction per donor. For the N1 and N2 primer probe sets, the fully synthetic SARS-CoV-2 RNA Control 2 from Twist Bioscience was loaded at serial 10-fold dilutions (A, 3×10 6 copies; B, 3×10 5 copies; C, 3×10 4 copies; D, 3×10 3 copies; E, 3×10 2 copies; F, 3×10 1 copies) as indicated in panels b and c . No template control (NTC) wells were included for each primer/probe set and each was negative. For panels b and c , the correlation coefficients (R 2 ) of the standard curves were 0.999 and 0.995, respectively. The dashed line at cycle 40 in each graph indicates the limit of detection."""
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