Volume 26, Number 8—August 2020
Synopsis
US CDC Real-Time Reverse Transcription PCR Panel for Detection of Severe Acute Respiratory Syndrome Coronavirus 2
Table 3
Limits of detection of the US CDC rRT-PCR panel for detection of SARS-CoV-2 with extracted SARS-CoV-2 virus RNA*
Virus concentration, TCID50 | N1 Ct |
N2 Ct |
N3 Ct |
|||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Test 1 | Test 2 | Test 3 | Call rate | Test 1 | Test 2 | Test 3 | Call rate | Test 1 | Test 2 | Test 3 | Call rate | |||
1 × 100.5 | 27.5 | 27.1 | 27.4 | 3/3 | 29.2 | 28.9 | 28.7 | 3/3 | 28.3 | 28.3 | 28.2 | 3/3 | ||
1 × 100 | 30.9 | 29.4 | 29.9 | 3/3 | 31.2 | 31.1 | 31.1 | 3/3 | 30.0 | 30.0 | 30.0 | 3/3 | ||
1 × 10−0.5 | 30.7 | 30.9 | 31.1 | 3/3 | 33.0 | 32.7 | 32.3 | 3/3 | 31.4 | 31.4 | 32.5 | 3/3 | ||
1 × 10−1 | 33.0 | 32.4 | 32.9 | 3/3 | 34.4 | 34.3 | 34.7 | 3/3 | 34.6 | 32.3 | 33.3 | 3/3 | ||
1 × 10−1.5 | 34.4 | 33.6 | 35.6 | 3/3 | 36.3 | 36.1 | 37.6 | 3/3 | 35.4 | 35.8 | 35.6 | 3/3 | ||
1 × 10−2 | 37.2 | 36.1 | Neg | 2/3 | 39.0 | Neg | Neg | 1/3 | 36.1 | Neg | Neg | 1/3 | ||
1 × 10-2.5 | 36.2 | 36.3 | Neg | 2/3 | 38.8 | 37.6 | Neg | 2/3 | 37.1 | Neg | Neg | 1/3 | ||
1 × 10−3 | Neg | Neg | Neg | 0/3 | Neg | Neg | Neg | 0/3 | Neg | Neg | Neg | 0/3 |
*Call rate indicates each assay performed in triplicate. CDC, Centers for Disease Control and Prevention; Ct, cycle threshold; N, nucleocapsid protein gene; neg, negative; rRT-PCR, real-time reverse transcription PCR; SARS-CoV-2, severe acute respiratory coronavirus 2; TCID50, 50% tissue culture infectious dose.