COVID-19 Diagnosis: Current and Future Techniques

Abstract

COVID-19 pandemic continues to be a global threat, affecting more than 200 countries/territories at both human and economic level. This necessitates the rapid development of highly reliable diagnostic methods in order to effectively and accurately diagnose the pathology to prevent the spread of COVID-19. Currently, RT-PCR is the most widely used method worldwide for SARS-CoV-2 detection. Serological assays are being used for sero-surveys of SARS-CoV-2 antibody prevalence in the community. Radiology imaging has been useful in the clinical diagnosis of COVID-19. These methods have their own limitations and there are continued efforts to develop easier, economic, highly sensitive and specific, point-of-care methods. Reverse transcription-loop mediated isothermal amplification (RT-LAMP), nucleic acid sequence-based amplification (NASBA), CRISPR-Cas-based detection, and digital PCR are such techniques being employed in research laboratories, with many awaiting diagnostic approval from competent authorities. This review highlights the rapidly expanding array of existing and in-development diagnostic tests/strategies that may be used to diagnose SARS-CoV-2 infection in both clinical and research settings.

Keywords: Biosensors; COVID-19; CRISPR-Cas; Diagnosis; Nanobodies; Nucleic acids; Serology.

Fig. 1

SARS-CoV-2 virion structure (S: spike protein, N: nucleocapsid protein; E: envelope protein and M: membrane protein).

Fig. 2

Methods for SARS-CoV-2 detection.

Fig. 3

Diagrammatical representation of (A) RT-PCR and (B) RT-LAMP based SARS-CoV-2 detection.

Fig. 4

CRISPR-Cas technologies for SARS-CoV-2 detection: (A) SHERLOCK; (B) DETECTR; (C) FELUDA.

Fig. 5

Schematic overview of lateral flow assay setup for SARS-CoV-2 detection.

Fig. 6

Schematic representation of nanobodies based detection of SARS-CoV-2.