FIG. 3.

Competitive assay standard curve for antiplague antibody with probes with immobilized rabbit antiplague IgG. To obtain the ratios, an initial signal (signal 1) was generated on the probes by addition of F1 antigen (200 ng/ml) for 5 min and then T-6H3-IgG (5 μg/ml) for 5 min. The second signal (signal 2) was obtained by repriming the probes with 500 ng of F1 antigen/ml and incubating them with various amounts of 6H3-IgG for 5 min and then with T-6H3-IgG for 5 min. The signal 2/signal 1 ratio versus 6H3-IgG concentration is shown. The mean ± standard error for three probes is shown at each concentration.