Table 2.
Resolution of inconclusive results from the CDC SARS-CoV-2 assay on Simplexa COVID-19 Direct.
| CDC SARS-CoV-2, Ct |
Simplexa COVID-19 Direct, Ct |
|||||||
|---|---|---|---|---|---|---|---|---|
| Samples | N1 | N2 | Rnase P | Interpretation | S | ORF1ab | IC | Interpretation |
| 1 | UND | 38.1 | 28.5 | INC | 32.5 | 32.8 | 30.2 | Positive |
| 1-repeat | UND | UND | 28.2 | Negative | ||||
| 2 | UND | 38.3 | 27.5 | INC | 0.0 | 39.1 | 30.9 | Positive |
| 2-repeat | UND | UND | 27.4 | Negative | ||||
| 3 | UND | 35.9 | 30.4 | INC | 30.1 | 31.2 | 31.2 | Positive |
| 3-repeat | UND | UND | 30.7 | Negative | ||||
| 4 | UND | 36.4 | 29.8 | INC | 32.9 | 37.6 | 31.3 | Positive |
| 4-repeat | UND | UND | 29.7 | Negative | ||||
| 5 | UND | 29.6 | 27.4 | INC | 0.0 | 0.0 | 30.5 | Negative |
| 5-repeat | UND | UND | 28.1 | Negative | ||||
| 6 | UND | 37.8 | 29.4 | INC | 32.2 | 32.6 | 29.8 | Positive |
| 6-repeat | N/A | N/A | N/A | N/A | ||||
| 7 | UND | 38.4 | 32.4 | INC | 0.0 | 0.0 | 30.5 | Positive |
| 7-repeat | N/A | N/A | N/A | N/A | ||||
| 8 | 37.0 | UND | 23.6 | INC | 32.5 | 32.1 | 29.8 | Positive |
| 8-repeat | N/A | N/A | N/A | N/A | ||||
| 9 | UND | 35.9 | 27.3 | INC | 34.5 | 37.4 | 27.8 | Positive |
| 9-repeat | N/A | N/A | N/A | N/A | ||||
UND = undetected; INC = inconclusive; N/A = not applicable; Rnase P = ribonuclease P; ORF = open reading frame target; IC = internal control.
Once Simplexa COVID-19 Direct assay was validated for clinical use, initial inconclusive results from the CDC assay (n = 4) were automatically reflexed to the Simplexa assay (patients 6, 7, 8, 9).