ArticlePloS one2022
RNA reference materials with defined viral RNA loads of SARS-CoV-2-A useful tool towards a better PCR assay harmonization.
Article in PloS one, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
24 citing papers in PubMed, 49 citations in OpenAlex.
- Trial
- Analytical and clinical evaluation of the Alinity m Resp-4-Plex assay in comparison to two singleplex SARS-CoV-2 assays and one multiplex respiratory assay.Microbiology spectrum · 2026Article
- Occurrence and clinical correlates of SARS-CoV-2 viremia in two German patient cohorts.Emerging microbes & infections · 2025Article
- Pseudovirus as an Emerging Reference Material in Molecular Diagnostics: Advancement and Perspective.Current issues in molecular biology · 2025Review
- Behind the scenes of EQA – characteristics, capabilities, benefits and assets of external quality assessment (EQA): Part V – Benefits for stakeholders other than participantsClinical chemistry and laboratory medicine · 2025Review
- Design, Immunogenicity and Preclinical Efficacy of the ChAdOx1.COVconsv12 Pan-Sarbecovirus T-Cell Vaccine.Vaccines · 2024Article
- Gut microbiota dysbiosis is associated with altered tryptophan metabolism and dysregulated inflammatory response in COVID-19.NPJ biofilms and microbiomes · 2024Article
- Standardization and Comparison of Emergency Use Authorized COVID-19 Assays and Testing Laboratories.medRxiv : the preprint server for health sciences · 2023Article
- Clinical comparison of three SARS-CoV-2 nucleic acid amplification tests for routine diagnostic testing.Heliyon · 2023Article
- Development of a national proficiency test for SARS-CoV-2 detection by PCR in Colombia.Journal of global health · 2023Article
- Correlation of SARS-CoV-2 RNA and nucleocapsid concentrations in samples used in INSTAND external quality assessment schemes.BMC research notes · 2023Article
- A culture-free method for rapidly and accurately quantifying active SARS-CoV-2.Analytical and bioanalytical chemistry · 2023Article
- Results of German external quality assessment schemes for SARS-CoV-2 antigen detection.Scientific reports · 2023Article
- Standardization of SARS-CoV-2 Cycle Threshold Values: Multisite Investigation Evaluating Viral Quantitation across Multiple Commercial COVID-19 Detection Platforms.Microbiology spectrum · 2023Article
- Converting to an international unit system improves harmonization of results for SARS-CoV-2 quantification: Results from multiple external quality assessments.Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology · 2023Article
- Results of the first German external quality assessment scheme for the detection of monkeypox virus DNA.PloS one · 2023Article
- Comparison and Harmonization of Different Semi-Automated and Automated qRT-PCR Assays in the Assessment of SARS-CoV-2.Viruses · 2022Article
- Evaluation of factors contributing to variability of qualitative and quantitative proficiency testing for SARS-CoV-2 nucleic acid detection.Biosafety and health · 2022Article
- Digital PCR Applications in the SARS-CoV-2/COVID-19 Era: a Roadmap for Future Outbreaks.Clinical microbiology reviews · 2022Review
- Accurate quantification of SARS-CoV-2 RNA by isotope dilution mass spectrometry and providing a correction of reverse transcription efficiency in droplet digital PCR.Analytical and bioanalytical chemistry · 2022Article
Corrections and comments
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Authors and funding
27 authors at 8 institutions in 4 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
SARS-CoV-2, the cause of COVID-19, requires reliable diagnostic methods to track the circulation of this virus. Following the development of RT-qPCR methods to meet this diagnostic need in January 2020, it became clear from interlaboratory studies that the reported Ct values obtained for the different laboratories showed high variability. Despite this the Ct values were explored as a quantitative cut off to aid clinical decisions based on viral load. Consequently, there was a need to introduce standards to support estimation of SARS-CoV-2 viral load in diagnostic specimens. In a collaborative study, INSTAND established two reference materials (RMs) containing heat-inactivated SARS-CoV-2 with SARS-CoV-2 RNA loads of ~107 copies/mL (RM 1) and ~106 copies/mL (RM 2), respectively. Quantification was performed by RT-qPCR using synthetic SARS-CoV-2 RNA standards and digital PCR. Between November 2020 and February 2021, German laboratories were invited to use the two RMs to anchor their Ct values measured in routine diagnostic specimens, with the Ct values of the two RMs. A total of 305 laboratories in Germany were supplied with RM 1 and RM 2. The laboratories were requested to report their measured Ct values together with details on the PCR method they used to INSTAND. This resultant 1,109 data sets were differentiated by test system and targeted gene region. Our findings demonstrate that an indispensable prerequisite for linking Ct values to SARS-CoV-2 viral loads is that they are treated as being unique to an individual laboratory. For this reason, clinical guidance based on viral loads should not cite Ct values. The RMs described were a suitable tool to determine the specific laboratory Ct for a given viral load. Furthermore, as Ct values can also vary between runs when using the same instrument, such RMs could be used as run controls to ensure reproducibility of the quantitative measurements.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.