Figure 2.

Western blot using gradient-purified West Nile virus antigen and sera (diluted 1/100) from sentinel chickens. Tracks 1 and 2, hyperimmune mouse serum prepared against WNV (positive control) or SINV (negative control) respectively; tracks 3 to 10 pairs of chicken sera that produced neutralization titres of 1/10, 1/20, 1/40, and 1/80 respectively.