Table 2.
Sensitivity of BinaxNOW for four relevant VOC versus Cycle threshold (Ct) values by RT-PCR.
| Ct range of CDC N2 gene (BinaxNOW—positive/total) | ||||
|---|---|---|---|---|
| 17–20 | 20–22 | 24–27 | 29–35 | |
| B.1.1.7a | 7/7 | 6/6 | 6/6 | 0/6 |
| B.1.2a | 7/7 | 6/6 | 6/6 | 0/6 |
| B.1.1.7b | 5/5 | nd | nd | nd |
| B.1.2b | 6/6 | nd | nd | nd |
| B.1.351b | nd | nd | 2/2 | nd |
| P.1b | 2/2 | 1/1 | nd | nd |
ND not determined. aPooled inactivated clinical samples. bIndividual non-inactivated clinical samples. RNA was purified from 140 µl aliquots by using QIAamp Viral RNA kit (Qiagen) or MagMax Viral RNA Isolation Kit (Applied Biosystems) and KingFisher Apex System (ThermoFisher), and were reversed transcribed into cDNA and amplified in a one-step RT-PCR multiplex reaction with qScript XLT one-Step RT-qPCR ToughMix (QuantaBio) using nCoV N2 combined primer/probe set (Integrated DNA Technologies, IDT), and the LightCycler 480 II instrument (Roche).