Related Experiment Video
Updated: Oct 20, 2025
Author Spotlight: Advancements in Multiplex Detection of Respiratory Viruses
Published on: November 10, 2023
Evaluation of two RT-PCR screening assays for identifying SARS-CoV-2 variants
M Migueres1, S Lhomme1, P Trémeaux2
1CHU Toulouse, Hôpital Purpan, Virology Laboratory, 31300, France; Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), INSERM UMR1291 - CNRS UMR5051, Toulouse 31300, France; Université Toulouse III Paul-Sabatier, Toulouse, France.
Background:
The recent emergence of new SARS CoV-2 variants (variants of concern, VOC) that spread rapidly and may lead to immune escape has emphasized the urgent need to monitor and control their spread.
Methods:
We analyzed 2018 SARS-CoV-2 positive specimens collected between February 9 and March 22, 2021 using the Thermofisher® TaqPath™ COVID-19 CE-IVD RT-PCR kit (TaqPath) and the ID solutions® ID™ SARS-CoV-2/UK/SA Variant Triplex RT-PCR (ID triplex) assay to screen for VOCs.
Results:
The ID triplex assay identified 62.8% of them as VOCs: 61.8% B.1.1.7 and 0.9% B.1.351/P.1. The agreement between the ID triplex results for B.1.1.7 and the TaqPath S gene target failure (SGTF)/ S gene target late detection (SGTL) profile for this variant agreed very well (k = 0.86). A low virus load was the main cause of discrepancies. Sequencing discordant results with both assays indicated that the TaqPath assay detected the B.1.1.7 lineage slightly better. Both assays suggested that the virus loads of B.1.1.7 variants were significantly higher than those of non-B.1.1.7 strains. Only 10/20 B1.351/P.1 strains detected with the ID triplex assay were confirmed by sequencing.
Conclusions:
We conclude that the SGTF/SGTL profiles identified using the TaqPath assay and ID triplex results are suitable for detecting the B.1.1.7 lineage. The ID triplex assay, which rapidly determines all three current VOCs simultaneously, could be a valuable tool for limiting virus spread by supporting contact-tracing and isolation.
