Table 3. Linearity studies.

Spiked level (% positive)	S1 Spike IgG	S1 Spike IgA	S1 Spike IgM
Level 1 (100%)	100%	100%	100%
Level 2 (75%)	103.4%	99.8%	99.5%
Level 3 (50%)	98.2%	98.6%	104.0%
Level 4 (25%)	103.7%	101.8%	96.7%
Level 5 (12.5%)	99.1%	102.1%	100.9%
Level 6 (6.25%)	95.5%	97.6%	98.2%
Spiked level (% positive)	Nucleoprotein IgG	Nucleoprotein IgA	Nucleoprotein IgM
Level 1 (100%)	100%	100%	100%
Level 2 (75%)	99.1%	99.8%	100.5%
Level 3 (50%)	104.1%	96.2%	95.7%
Level 4 (25%)	103.5%	104.6%	102.3%
Level 5 (12.5%)	98.9%	96.1%	98.1%
Level 6 (6.25%)	95.1%	102.3%	98.8%
Spiked level (% positive)	RBD IgG	RBD IgA	RBD IgM
Level 1 (100%)	100%	100%	100%
Level 2 (75%)	100.8%	101.0%	104.0%
Level 3 (50%)	97.2%	97.9%	97.8%
Level 4 (25%)	104.0%	97.0%	101.2%
Level 5 (12.5%)	100.2%	97.9%	98.1%
Level 6 (6.25%)	100.1%	101.3%	97.2%
Spiked level (% positive)	S2 Spike IgG	S2 Spike IgA	S2 Spike IgM
Level 1 (100%)	100%	100%	100%
Level 2 (75%)	100.8%	97.3%	100.4%
Level 3 (50%)	102.0%	97.8%	100.5%
Level 4 (25%)	104.0%	98.5%	101.5%
Level 5 (12.5%)	97.7%	102.1%	95.6%
Level 6 (6.25%)	97.6%	99.2%	101.5%