Table 4.

Inter-batch variation in antigen-capture enzyme-linked immunosorbent assay (AC-ELISA) detection of the H9N2 subtype avian influenza virus

HA titer	OD value in inter-batch			Mean ± SD	CV%a
	1 day	30 days	60 days
25	1.197	1.116	1.138	1.150 ± 0.042	3.6
24	0.841	0.861	0.872	0.858 ± 0.016	1.9
23	0.563	0.565	0.535	0.554 ± 0.017	3.0
22	0.330	0.337	0.358	0.341 ± 0.015	4.3
21	0.157	0.155	0.168	0.160 ± 0.007	4.3
20	0.081	0.082	0.077	0.080 ± 0.003	3.4

^aCV%, coefficient of variation