TABLE 1.

Comparison of the methods.

	In-house immuno-fluorescent assay	EUROIMMUN ELISA SARS-CoV-2 IgG	NovaLisa SARS-CoV-2 IgG and IgM	T-Tek SARS-CoV-2 IgG/IgM antibody Test Kit	Sure Bio-tech SARS-CoV-2 IgM/IgG antibody Rapid Test
Method	Indirect immunofluorescence	ELISA	ELISA	Immunochromatography	Immunochromatography
Class of antibodies	IgG, IgM, and IgA	IgG	IgG and IgM (2 kits)	IgG and IgM (1 cassette)	IgG and IgM (1 cassette)
Antigen(s)	Inactivated infected cells	Recombinant S1 protein	Recombinant N protein	Recombinant N, S, and RBD proteins	Recombinant N and S proteins
Time	±3 h	±2.5 h	±2 h	15 min	15 min
Medium	Serum or plasma	Serum or plasma	Serum or plasma	Serum, plasma, or whole blood	Serum, plasma, or whole blood
Test sample	25 μL	10 μL	10 μL	10 μL	10 μL
Interpretation	Fluorescence microscope reading	Determination of a score to cut-off ratio	Determination of a score to cut-off ratio	Direct reading	Direct reading

N, nucleocapside protein; S, spike protein; RBD, receptor-binding domain.