TABLE 1.

Attributes for the evaluated anti-SARS-CoV-2 IgG serologic assays^a

Attribute	Data for:
	Abbott	Epitope	Euroimmun	Ortho-Clinical
Assay principleb	CMIA	ELISA	ELISA	CLIA
Solid-phase antigen	Nucleocapsid	Nucleocapsid	Spike S1	Spike
Specimen type	Serum, plasma	Serum	Serum	Serum
Sample volume	25 μl	10 μl	10 μl	20 μl
EUA status	Granted	Submitted	Granted	Granted
Result calculation	Index (S/Co)	Index (S/Co)	Index (S/Co)	Index (S/Co)
Positive cutoff threshold	≥1.4	≥1.21c	≥1.1	≥1.00
Indeterminate cutoff range	NA	≥1.01 to <1.21c	≥0.8 to <1.1	NA
Operational type	Continuous, random access	Batch	Batch	Continuous, random access
Time to first result	29 min	80 min	120 min	48 min
Test throughput per 8 h	1,600	630c	630d	1,040 to 1,200

^aAbbreviations: CMIA, chemiluminescent microparticle immunoassay; ELISA, enzyme-linked immunosorbent assay; CLIA, chemiluminescence immunoassay; EUA, emergency use authorization; S/Co, signal-to-cutoff; NA, not applicable.

^bAll assays are indirect in format.

^cLaboratory-determined cutoff threshold.

^dTesting performed on the Dynex Agility automated ELISA processor (Chantilly, VA).