SARS-CoV-2 Viral RNA Detection Using the Novel Covradar Device Associated with the CoVreader Smartphone App
15 Pages Posted: 28 Nov 2022
Abstract
COVID-19 pandemic has pointed out the strong need to continue promoting the development of innovative approaches for the rapid, safe handling and accurate molecular diagnosis of SARS-CoV-2 infection. In this work, we have developed CoVradar, a novel colourimetric molecular detection system that integrates nucleic acid analysis by dynamic chemistry labelling (DCL) technology with the Spin-Tube devices allowing reverse dot-blot hybridization in an array format to detect SARS-CoV-2 RNA within saliva specimens. The assay is designed so that ten regions per RNA copy act as templates to amplify the signal generated through a DCL reaction. The sequences are captured by abasic peptide nucleic acids (DGL-Probes) immobilised onto nylon membranes with a specific spot pattern. Biotinylated SMART-Bases are used for the labelling of duplexes formed upon the capture of complementary ssRNA fragment sequences that act as templates. Signals are then generated by the recognition of the biotin via streptavidin alkaline phosphatase and incubation with a chromogenic substrate which generates a blue precipitate. CoVradar’s results are automatically interpreted by CoVreader, a dedicated smartphone-based Image Processing System (IPS) capable of imaging and analysing the spot pattern developed to record and share results by mobile phone. The combination of CoVradar and CoVreader delivers a unique molecular assay capable of detecting SARS-CoV-2 viral RNA with single base specificity. This represents an innovative solution providing benefits in terms of time, cost, and simplicity, all of which are crucial for the diagnosis of COVID-19 but also in time, a repertoire of assays for other infectious diseases.
Note:
Funding Information: This research work has been funding by FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento/ Project CV20-77741. This study was also partially funded by : (i) Spanish MCIN/ AEI/10.13039/501100011033/ Projects PID2019-110987RB-I00 and PID2019-103938RB-I00; (ii) FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento/ Projects P18-RT-2961, P18-TP-4160 and A-FQM-760-UGR20 and (iii) FEDER/Junta de Andalucía-Consejería de Salud y Familias/ Project PIP-0232-2021. The projects were partially supported by European Regional Development Funds (ERDF). C. Martin-Sierra and P. Escobedo thank respectively grants PTQ2020-011388 and IJC2020-043307-I both of them funded by MCIN/AEI/10.13039/501100011033 and by “European Union NextGenerationEU/PRTR”.
Conflict of Interests: The authors declare the following financial interests which may be considered as potential competing interests: JJDM is a founder, shareholder and Director of DESTINA Genomics Ltd. SP is a shareholder of DESTINA Genomics Ltd. DESTINA Genomica SL is a wholly-owned subsidiary of DESTINA Genomics Ltd. DESTINA is interested in the exploitation of the technology developed here.
Ethical Approval: Saliva samples were provided by the Biobank of the Public Health System of Andalusia. Informed consent was given by all the individuals enrolled in this study.
Keywords: SARS-CoV-2, COVID-19 test, Colourimetric Assay, Nucleic acid detection, Dynamic Chemistry Labelling (DCL), Image Processing System (IPS)
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