tetano
Editor, Senior Moderator
J Virol Methods
. 2021 Feb 9;291:114086.
doi: 10.1016/j.jviromet.2021.114086. Online ahead of print.
Evaluation of three extraction-free SARS-CoV-2 RT-PCR assays: a feasible alternative approach with low technical requirements
Benoit Visseaux[SUP] 1 [/SUP], Gilles Collin[SUP] 1 [/SUP], Nadhira Houhou-Fidouh[SUP] 1 [/SUP], Quentin Le Hingrat[SUP] 1 [/SUP], Valentine Marie Ferr?[SUP] 1 [/SUP], Florence Damond[SUP] 1 [/SUP], Houria Ichou[SUP] 1 [/SUP], Diane Descamps[SUP] 1 [/SUP], Charlotte Charpentier[SUP] 2 [/SUP]
Affiliations
Abstract
The worldwide demand for SARS-CoV-2 RT-PCR testing resulted in a shortage of diagnostic kits. RNA extraction step constitutes a major bottleneck to perform diagnostic. The aim of this study was to assess performances of different extraction-free SARS-CoV-2 RT-PCR assays compared to a reference RT-PCR assay. The panel of evaluation consisted of 94 samples: 69 positive and 25 negative for SARS-CoV-2 by reference RT-PCR. Three extraction-free RT-PCR assays were assessed: (i) PrimeDirect? Probe RT-qPCR Mix (Takara), (ii) PrimeScript?RT-PCR (Takara), and (iii) SARS-CoV-2 SANSURE?BIOTECH Novel Coronavirus (Sansure). The overall sensitivity of PrimeDirect, PrimeScript and Sansure assays was 55.1%, 69.6% and 69.6%, respectively. The sensitivity increased among samples with Ct<30: 91.9% (n = 34/37), 89.2% (n = 33/37) and 94.6% (n = 35/37) for PrimeDirect, PrimeScript and Sansure assays, respectively. The specificity was 88%, 100% and 100% for PrimeDirect, PrimeScript and Sansure assays, respectively. In the present study, we showed a good sensitivity of extraction-free PCR assays, especially for high viral loads (Ct<30), except PrimeDirect that displayed imperfect sensitivity and specificity. Despite a lower sensitivity for low viral loads, extraction-free reagents can provide a valuable option, cheaper, easier and less reagent consuming for SARS-CoV-2 diagnostic, especially in laboratory with lower experience and equipment for molecular assays.
Keywords: RT-PCR; SARS-CoV-2; extraction-free.
. 2021 Feb 9;291:114086.
doi: 10.1016/j.jviromet.2021.114086. Online ahead of print.
Evaluation of three extraction-free SARS-CoV-2 RT-PCR assays: a feasible alternative approach with low technical requirements
Benoit Visseaux[SUP] 1 [/SUP], Gilles Collin[SUP] 1 [/SUP], Nadhira Houhou-Fidouh[SUP] 1 [/SUP], Quentin Le Hingrat[SUP] 1 [/SUP], Valentine Marie Ferr?[SUP] 1 [/SUP], Florence Damond[SUP] 1 [/SUP], Houria Ichou[SUP] 1 [/SUP], Diane Descamps[SUP] 1 [/SUP], Charlotte Charpentier[SUP] 2 [/SUP]
Affiliations
- PMID: 33577957
- PMCID: PMC7871772
- DOI: 10.1016/j.jviromet.2021.114086
Abstract
The worldwide demand for SARS-CoV-2 RT-PCR testing resulted in a shortage of diagnostic kits. RNA extraction step constitutes a major bottleneck to perform diagnostic. The aim of this study was to assess performances of different extraction-free SARS-CoV-2 RT-PCR assays compared to a reference RT-PCR assay. The panel of evaluation consisted of 94 samples: 69 positive and 25 negative for SARS-CoV-2 by reference RT-PCR. Three extraction-free RT-PCR assays were assessed: (i) PrimeDirect? Probe RT-qPCR Mix (Takara), (ii) PrimeScript?RT-PCR (Takara), and (iii) SARS-CoV-2 SANSURE?BIOTECH Novel Coronavirus (Sansure). The overall sensitivity of PrimeDirect, PrimeScript and Sansure assays was 55.1%, 69.6% and 69.6%, respectively. The sensitivity increased among samples with Ct<30: 91.9% (n = 34/37), 89.2% (n = 33/37) and 94.6% (n = 35/37) for PrimeDirect, PrimeScript and Sansure assays, respectively. The specificity was 88%, 100% and 100% for PrimeDirect, PrimeScript and Sansure assays, respectively. In the present study, we showed a good sensitivity of extraction-free PCR assays, especially for high viral loads (Ct<30), except PrimeDirect that displayed imperfect sensitivity and specificity. Despite a lower sensitivity for low viral loads, extraction-free reagents can provide a valuable option, cheaper, easier and less reagent consuming for SARS-CoV-2 diagnostic, especially in laboratory with lower experience and equipment for molecular assays.
Keywords: RT-PCR; SARS-CoV-2; extraction-free.