TABLE 2.

Comparison of different SARS-CoV-2 nucleic acid detection methods.

Methods	Sample types	Absolute quantification	Sophisticated instrument	Time	LOD	Target gene	Advantages	Disadvantages
Sequencing	Nasopharyngeal swab	N	Y	2–3 days	—	—	More precise, genomic profiling, new mutations detection	Time-consuming, expensive, specialized operators
RT-PCR	Nasopharyngeal swab, sputum, bronchoalveolar lavage fluid, stool	Y	Y	70–120 min	100 copies/ml	ORF1ab, N	Mature technology, complete supporting reagents, absolute quantification, low cost	Thermal cycling, specialized operators, time-consuming
RT-LAMP	Nasopharyngeal swab, sputum, stool	N	N	30–60 min	1 copies/μl	ORF1ab, N	Isothermal, simple, rapid, highly sensitive	Non-specific amplification, too many primers, ladder band
RT-RPA	Nasopharyngeal swab, sputum, stool	N	N	20–40 min	0.25–2.5 copies/μl	N	Isothermal, simple, rapid, highly sensitive	Non-specific amplification, no primer design software, too many enzymes in system
CRISPR-based assay	Nasopharyngeal swab, bronchoalveolar lavage fluid	N	N	30–60 min	0.9–10 copies/μl	ORF1ab, N, E	Isothermal, amplify the signal, easy to combine with isothermal amplification	Immature technology, reaction system to be optimized
Biosensors and microfluidics	Nasopharyngeal swab, sputum, bronchoalveolar lavage fluid	N	N	60 min	0.5 copies/μl	N, M	Miniaturization, simple, real-time detection	Sensitive to surrounding environment, complex design, high cost