The real-time reverse transcription-polymerase chain reaction threshold cycle values for severe acute respiratory syndrome coronavirus 2 predict the prognosis of coronavirus disease 2019 pneumonia

Abstract Background Pandemic coronavirus disease 2019 (COVID-19) disease represents a challenge for healthcare structures. The molecular confirmation of samples from infected individuals is crucial and therefore guides public health decision making. Clusters and possibly increased diffuse transmission could occur in the context of the next influenza season. For this reason, a diagnostic test able to discriminate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from influenza viruses is urgently needed. Methods A multiplex real-time reverse-transcription polymerase chain reaction (PCR) assay was assessed using 1 laboratory protocol with different real-time PCR instruments. Overall, 1000 clinical samples (600 from samples SARS-CoV-2–infected patients, 200 samples from influenza-infected patients, and 200 negative samples) were analyzed. Results The assay developed was able to detect and discriminate each virus target and to intercept coinfections. The limit of quantification of each assay ranged between 5 and 10 genomic copy numbers, with a cutoff value of 37.7 and 37.8 for influenza and SARS-CoV-2 viruses, respectively. Only 2 influenza coinfections were detected in COVID-19 samples. Conclusions This study suggests that multiplex assay is a rapid, valid, and accurate method for the detection of SARS-CoV-2 and influenza viruses in clinical samples. The test may be an important diagnostic tool for both diagnostic and surveillance purposes during the seasonal influenza activity period.

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Comparison of real-time polymerase chain reaction and end-point polymerase chain reaction for the analysis of gene expression in preimplantation embryos

Reproduction Fertility and Development ◽

10.1071/rd05012 ◽

2006 ◽

Vol 18 (3) ◽

pp. 365 ◽

Cited By ~ 17

Author(s):

Árpád Baji Gál ◽

Joseph Wallace Carnwath ◽

Andras Dinnyes ◽

Doris Herrmann ◽

Heiner Niemann ◽

...

Keyword(s):

Gene Expression ◽

Polymerase Chain Reaction ◽

Real Time ◽

Reverse Transcription ◽

Dynamic Range ◽

Chain Reaction ◽

Real Time System ◽

The Real ◽

End Point ◽

Polymerase Chain

The aim of the present study was to compare real-time polymerase chain reaction (PCR) and end-point PCR with respect to their suitability for the analysis of gene expression in samples in which the number of cells is limited; for example, in studies of preimplantation embryonic development and to determine the variability of the real-time reverse transcription–PCR assay. The sensitivity, dynamic range and precision of both PCR systems were compared using a single mouse liver cDNA standard. The real-time system was 100-fold more sensitive than the end-point system and had a dynamic range of more than four orders of magnitude. The linear range for end-point PCR extended for two orders of magnitude using a fixed end-point of 31 cycles. The percentage standard error of the mean based on 30 replicates was 0.14% of the threshold cycle (Ct) value for the real-time system and 6.8% for the end-point fluorescence intensity. The coefficients of variation (CV) for reverse transcription combined with real-time analysis and the complete gene expression protocol consisting of mRNA isolation, reverse transcription and real-time PCR analysis were 0.6% and 1.4% of the Ct values, respectively. The present paper details, for the first time, measurement of the biological variation of individual mammalian oocytes. The CV was 1.8% of the Ct value for expression analysis of six bovine oocytes. The results are discussed in relation to the analysis of gene expression in preimplantation embryo development.

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Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in Febrile Infants Without Respiratory Distress

Clinical Infectious Diseases ◽

10.1093/cid/ciaa452 ◽

2020 ◽

Vol 71 (16) ◽

pp. 2243-2245 ◽

Cited By ~ 15

Author(s):

Michal Paret ◽

Jennifer Lighter ◽

Rebecca Pellett Madan ◽

Vanessa N Raabe ◽

Gail F Shust ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Severe Acute Respiratory Syndrome ◽

Respiratory Distress ◽

Real Time ◽

Reverse Transcription ◽

Bacterial Infections ◽

Chain Reaction ◽

Polymerase Chain

Abstract We report 2 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19) in infants presenting with fever in the absence of respiratory distress who required hospitalization for evaluation of possible invasive bacterial infections. The diagnoses resulted from routine isolation and real-time reverse-transcription polymerase chain reaction–based testing for SARS-CoV-2 for febrile infants in an outbreak setting.

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