Table  Comparison of two different one-step real-time RT-PCR systems with SARS-CoV-2 assays from Corman et al. [5] and a commercial test kit with kit-specific assays, Bavaria, February 2020
Real-time RT-PCR system  PCR efficiency (%)a, linearity (R2)  Limit of detection (copies/reaction)  Unspecific signals count in E gene assay in totalb  Unspecific signals in E gene assay (%)b  Run time (hours)
QuantiTect Virus +Rox Vial kit (QIAGEN)  ND  ND  451/743(75/126 NC, 376/617 patient samples)  60.7  1:50
SuperScript III One-step RT-PCR System with Platinum TaqDNA Polymerase (Invitrogen)  95 / 0,99c  50c  13/257(2/38 NC,11/219 patient samples)  5.1  1:28
RealStar SARS-CoV-2 RT-PCR kit 1.0 (Altona)  125 / 0,97d  10d  0/111(0/38 NC, 0/73 patients samples)  0  2:15
NC: negative control samples; ND: not determined.
a E = 10−1/slope − 1.
b Indicated counts and percentage values of unspecific background signals in the SARS-CoV E gene assay are based on the total number of tested patient samples as well as the negative extraction and non-template controls.
c Only for RdRp gene assays, tested with four replicates of SARS-CoV Frankfurt 1 RNA [6]; 10-fold serial dilutions were determined. For the E gene, the assay was not linear.
d Only for the E gene, tested with two replicates of synthetic Wuhan coronavirus 2019 E gene control and SARS-CoV Frankfurt 1 RNA each [6]; 10-fold serial dilutions were determined.