Recent advances in RNA sample preparation techniques for the detection of SARS-CoV-2 in saliva and gargle

https://doi.org/10.1016/j.trac.2023.117107Get rights and content
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open access

Highlights

  • Saliva and gargle complement nasopharyngeal swab samples for SARS-CoV-2 detection.

  • Several advantages of self-collection of saliva and gargle samples.

  • On-site inactivation of virus and preservation of RNA are necessary.

  • Heating and chemical treatment of samples increase RNA extraction efficiency.

  • Concentration of viral RNA and removal of inhibitors improve detection sensitivity.

Abstract

Molecular detection of SARS-CoV-2 in gargle and saliva complements the standard analysis of nasopharyngeal swabs (NPS) specimens. Although gargle and saliva specimens can be readily obtained non-invasively, appropriate collection and processing of gargle and saliva specimens are critical to the accuracy and sensitivity of the overall analytical method. This review highlights challenges and recent advances in the treatment of gargle and saliva samples for subsequent analysis using reverse transcription polymerase chain reaction (RT-PCR) and isothermal amplification techniques. Important considerations include appropriate collection of gargle and saliva samples, on-site inactivation of viruses in the sample, preservation of viral RNA, extraction and concentration of viral RNA, removal of substances that inhibit nucleic acid amplification reactions, and the compatibility of sample treatment protocols with the subsequent nucleic acid amplification and detection techniques. The principles and approaches discussed in this review are applicable to molecular detection of other microbial pathogens.

Keywords

COVID-19
Gargle and saliva
Isothermal amplification (LAMP and RPA)
Molecular diagnostics
Nucleic acids
Point-of-care
RT-PCR
Sampling and treatment
Viral RNA
Microbial pathogens
SARS-CoV-2

Data availability

Data will be made available on request.

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