Development and evaluation of a Novel RT-PCR system for reliable and rapid SARS-CoV-2 screening of blood donations.

The ongoing outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused great global concerns. In contrast to SARS, some SARS-CoV-2-infected people can be asymptomatic or have only mild nonspecific symptoms. Furthermore, there is evidence that SARS-CoV-2 may be infectious during an asymptomatic incubation period. With the discovery that SARS-CoV-2 can be detected in plasma or serum, blood safety is worthy of consideration. We developed a nucleic acid test (NAT) screening system for SARS-CoV-2 targeting nucleocapsid protein (N) and open reading frame 1ab (ORF 1ab) gene that could screen 5076 samples every 24 hours. The 2019 novel coronavirus RNA standard was used to evaluate linearity of standard curves. Diagnostic sensitivity and reproducibility were evaluated using artificial SARS-CoV-2. Specificity was evaluated with 61 other respiratory pathogens. Diagnostic performance was evaluated by testing two sputum and nine oropharyngeal swab specimens. The reverse transcription polymerase chain reaction (RT-PCR) assay was used to screen SARS-CoV-2 RNA in blood donor specimens collected during the outbreak of SARS-CoV-2 in Chengdu. Limits of detection of the SARS-CoV-2 RT-PCR assay for N and ORF 1ab gene were 12.5 and 27.58 copies/mL, respectively. Intra-assay and interassay for the SARS-CoV-2 RT-PCR assay based on cycle threshold were acceptably low. No cross-reactivity was observed with other respiratory virus and bacterial isolates. The overall agreement value between the SARS-CoV-2 RT-PCR assay and clinical diagnostic results was 100%. A total of 16 287 blood specimens collected from blood donors during SARS-CoV-2 surveillance were tested negative. A high-throughput NAT screening system was developed for SARS-CoV-2 screening of blood donations during the outbreak of SARS-CoV-2.

Li M ，Zhao Y ，Li Y ，Chen X ，Luo D ，Luo M ，Hou J ，Liu J ，Liu H ，Wang H ，Dong Y ，Zhang L ，Ji M ，Zhao X ，Wei C ，Li W ，Gao J ，Shan H ，Fu X ... -  《-》

A semi-automated, isolation-free, high-throughput SARS-CoV-2 reverse transcriptase (RT) loop-mediated isothermal amplification (LAMP) test.

Shortages of reverse transcriptase (RT)-polymerase chain reaction (PCR) reagents and related equipment during the COVID-19 pandemic have demonstrated the need for alternative, high-throughput methods for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-mass screening in clinical diagnostic laboratories. A robust, SARS-CoV-2 RT-loop-mediated isothermal amplification (RT-LAMP) assay with high-throughput and short turnaround times in a clinical laboratory setting was established and compared to two conventional RT-PCR protocols using 323 samples of individuals with suspected SARS-CoV-2 infection. Limit of detection (LoD) and reproducibility of the isolation-free SARS-CoV-2 RT-LAMP test were determined. An almost perfect agreement (Cohen's kappa > 0.8) between the novel test and two classical RT-PCR protocols with no systematic difference (McNemar's test, P > 0.05) was observed. Sensitivity and specificity were in the range of 89.5 to 100% and 96.2 to 100% dependent on the reaction condition and the RT-PCR method used as reference. The isolation-free RT-LAMP assay showed high reproducibility (Tt intra-run coefficient of variation [CV] = 0.4%, Tt inter-run CV = 2.1%) with a LoD of 95 SARS-CoV-2 genome copies per reaction. The established SARS-CoV-2 RT-LAMP assay is a flexible and efficient alternative to conventional RT-PCR protocols, suitable for SARS-CoV-2 mass screening using existing laboratory infrastructure in clinical diagnostic laboratories.

Schmidt J ，Berghaus S ，Blessing F ，Wenzel F ，Herbeck H ，Blessing J ，Schierack P ，Rödiger S ，Roggenbuck D ... -  《Scientific Reports》

Sensitive tracking of circulating viral RNA through all stages of SARS-CoV-2 infection.

Huang Z ，Ning B ，Yang HS ，Youngquist BM ，Niu A ，Lyon CJ ，Beddingfield BJ ，Fears AC ，Monk CH ，Murrell AE ，Bilton SJ ，Linhuber JP ，Norton EB ，Dietrich ML ，Yee J ，Lai W ，Scott JW ，Yin XM ，Rappaport J ，Robinson JE ，Saba NS ，Roy CJ ，Zwezdaryk KJ ，Zhao Z ，Hu TY ... -  《-》

Molecular Mirror Technology Facilitates High-Throughput, Accurate SARS-CoV-2 Testing.

Realegeno S ，Hash S ，Wong C ，Liu R ，Shepherd J ，Schooley RT ，Lipson DA ，Fung F ，Menon S ，Pride DT ... -  《Microbiology Spectrum》

Development and Evaluation of AccuPower COVID-19 Multiplex Real-Time RT-PCR Kit and AccuPower SARS-CoV-2 Multiplex Real-Time RT-PCR Kit for SARS-CoV-2 Detection in Sputum, NPS/OPS, Saliva and Pooled Samples.

Suh IB ，Lim J ，Kim HS ，Rhim G ，Kim H ，Kim H ，Lee SM ，Park HS ，Song HJ ，Hong M ，Shin GS ，Kim MJ ... -  《PLoS One》