FIG. 4.

Correlation between the VPX-based ELISA and commercial kits. OD measurements using the IDEXX kit were obtained by diluting the chicken sera 1/500 and were compared with those obtained from serum dilutions of 1/100 (A) and 1/500 (B) in the VPX ELISA. When the KPL kit was used, chicken sera were diluted 1/100 and OD values were compared with those obtained from serum dilutions of 1/100 (C) and 1/500 (D) in the VPX ELISA. The linear regression formula and correlation coefficient are shown at the top of each plot.