Table 1.

Dual labeling of IBV N protein in Vero and CEK cells indicated a significant linear increase in the ³²P:³H ratio (P < 0.0001) of IBV N protein with the time post-infection

Time of harvest: hours post-infection	Chicken embryo kidney cellsa	Vero cellsa
7	0.35 ± 0.004	0.24 ± 0.004
9	0.83 ± 0.036	0.45 ± 0.003
11	0.80 ± 0.074	0.84 ± 0.001
13	0.73 ± 0.017	0.85 ± 0.056
16 (Virion N)	1.22 ± 0.004	2.52 ± 0.006

^aRepresents cpm ratios of ³²P:³H ± standard deviation.