We described an one-step end-point RT-PCR for molecular detection of the SARS-CoV-2 E gene.
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The analytical sensitivity of the RT-PCR was about 7.15–9 copies of vRNA/μL.
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The RT-PCR was able to detect SARS-CoV-2 infection in asymptomatic individuals.
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Nonspecific amplifications were not observed in SARS-CoV-2 negative samples.
Abstract
Real-time reverse transcription-polymerase chain reaction (RT-qPCR) is considered the "gold standard" for the direct diagnosis of SARS-CoV-2 infections. However, routine diagnosis by RT-qPCR is a limitation for many laboratories, mainly due to the infrastructure and/or disproportionate relationship between demand and supply of inputs. In this context, and to increase the diagnostic coverage of SARS-CoV-2 infections, we describe an alternative, sensitive and specific one-step end-point RT-PCR for the detection of the SARS-CoV-2 E gene. The performance of the RT-PCR was evaluated in 43 clinical samples, of which 10 and 33 were previously identified as negative and positive, respectively, by RT-qPCR. Among the positive samples, 15 and 18 were from asymptomatic and symptomatic individuals, respectively. Here, 32/33 of the positive samples in the RT-qPCR, including from asymptomatic individuals, were found positive in the RT-PCR (Ct 15.94–34.92). The analytical sensitivity of the assay was about 7.15–9 copies of vRNA/μL, and nonspecific amplifications were not observed in SARS-CoV-2 negative samples. Importantly, the RT-PCR reactions were performed in a 10 μL final volume. Finally, considering specificity, analytical sensitivity and cost reduction, we believe that the RT-PCR platform described here may be a viable option for the diagnostic of SARS-CoV-2 infections in laboratories in which RT-qPCR is not available.
