tetano
Editor, Senior Moderator
Anal Chem
. 2021 May 25.
doi: 10.1021/acs.analchem.0c05170. Online ahead of print.
Reverse Transcription Loop-Mediated Isothermal Amplification Assay for Ultrasensitive Detection of SARS-CoV-2 in Saliva and Viral Transport Medium Clinical Samples
Anurup Ganguli[SUP] 1 2 [/SUP], Ariana Mostafa[SUP] 1 2 [/SUP], Jacob Berger[SUP] 1 2 [/SUP], Jongwon Lim[SUP] 1 2 [/SUP], Elbashir Araud[SUP] 2 [/SUP], Janice Baek[SUP] 1 3 [/SUP], Sarah A Stewart de Ramirez[SUP] 4 [/SUP], Ali Baltaji[SUP] 5 [/SUP], Kelly Roth[SUP] 5 [/SUP], Muhammad Aamir[SUP] 5 [/SUP], Surya Aedma[SUP] 5 [/SUP], Mohamed Mady[SUP] 5 [/SUP], Pranav Mahajan[SUP] 5 [/SUP], Sanjivani Sathe[SUP] 5 [/SUP], Mark Johnson[SUP] 5 6 [/SUP], Karen White[SUP] 5 6 [/SUP], James Kumar[SUP] 5 6 [/SUP], Enrique Valera[SUP] 1 2 [/SUP], Rashid Bashir[SUP] 1 2 3 6 [/SUP]
Affiliations
Abstract
The COVID-19 pandemic has underscored the shortcomings in the deployment of state-of-the-art diagnostics platforms. Although several polymerase chain reaction (PCR)-based techniques have been rapidly developed to meet the growing testing needs, such techniques often need samples collected through a swab, the use of RNA extraction kits, and expensive thermocyclers in order to successfully perform the test. Isothermal amplification-based approaches have also been recently demonstrated for rapid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection by minimizing sample preparation while also reducing the instrumentation and reaction complexity. In addition, there are limited reports of saliva as the sample source, and some of these indicate inferior sensitivity when comparing reverse transcription loop-mediated isothermal amplification (RT-LAMP) with PCR-based techniques. In this paper, we demonstrate an improved sensitivity assay from saliva using a two-step RT-LAMP assay, where a short 10 min RT step is performed with only B3 and backward inner primers before the final reaction. We show that while the one-step RT-LAMP demonstrates satisfactory results, the optimized two-step approach allows detection of only few molecules per reaction and performs significantly better than the one-step RT-LAMP and conventional two-step RT-LAMP approaches with all primers included in the RT step. We show control measurements with RT-PCR, and importantly, we demonstrate RNA extraction-free RT-LAMP-based assays for detection of SARS-CoV-2 from viral transport media and saliva clinical samples.
. 2021 May 25.
doi: 10.1021/acs.analchem.0c05170. Online ahead of print.
Reverse Transcription Loop-Mediated Isothermal Amplification Assay for Ultrasensitive Detection of SARS-CoV-2 in Saliva and Viral Transport Medium Clinical Samples
Anurup Ganguli[SUP] 1 2 [/SUP], Ariana Mostafa[SUP] 1 2 [/SUP], Jacob Berger[SUP] 1 2 [/SUP], Jongwon Lim[SUP] 1 2 [/SUP], Elbashir Araud[SUP] 2 [/SUP], Janice Baek[SUP] 1 3 [/SUP], Sarah A Stewart de Ramirez[SUP] 4 [/SUP], Ali Baltaji[SUP] 5 [/SUP], Kelly Roth[SUP] 5 [/SUP], Muhammad Aamir[SUP] 5 [/SUP], Surya Aedma[SUP] 5 [/SUP], Mohamed Mady[SUP] 5 [/SUP], Pranav Mahajan[SUP] 5 [/SUP], Sanjivani Sathe[SUP] 5 [/SUP], Mark Johnson[SUP] 5 6 [/SUP], Karen White[SUP] 5 6 [/SUP], James Kumar[SUP] 5 6 [/SUP], Enrique Valera[SUP] 1 2 [/SUP], Rashid Bashir[SUP] 1 2 3 6 [/SUP]
Affiliations
- PMID: 34033472
- DOI: 10.1021/acs.analchem.0c05170
Abstract
The COVID-19 pandemic has underscored the shortcomings in the deployment of state-of-the-art diagnostics platforms. Although several polymerase chain reaction (PCR)-based techniques have been rapidly developed to meet the growing testing needs, such techniques often need samples collected through a swab, the use of RNA extraction kits, and expensive thermocyclers in order to successfully perform the test. Isothermal amplification-based approaches have also been recently demonstrated for rapid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection by minimizing sample preparation while also reducing the instrumentation and reaction complexity. In addition, there are limited reports of saliva as the sample source, and some of these indicate inferior sensitivity when comparing reverse transcription loop-mediated isothermal amplification (RT-LAMP) with PCR-based techniques. In this paper, we demonstrate an improved sensitivity assay from saliva using a two-step RT-LAMP assay, where a short 10 min RT step is performed with only B3 and backward inner primers before the final reaction. We show that while the one-step RT-LAMP demonstrates satisfactory results, the optimized two-step approach allows detection of only few molecules per reaction and performs significantly better than the one-step RT-LAMP and conventional two-step RT-LAMP approaches with all primers included in the RT step. We show control measurements with RT-PCR, and importantly, we demonstrate RNA extraction-free RT-LAMP-based assays for detection of SARS-CoV-2 from viral transport media and saliva clinical samples.