Development of ELISA based on Bacillus anthracis capsule biosynthesis protein CapA for naturally acquired antibodies against anthrax
Fig 3
Horses anti-PAD1 immunoglobulin G (IgG) responses against subcutaneously injected Bacillus anthracis Sterne 34F2 strain spore vaccine.
(A) anti-PAD1 IgG response of vaccinated horses in serum dilution 1:100. Each serum sample was tested in technical triplicate by PAD1-ELISA. Checkerboard titration between PAD1 and (B) horse hyperimmunized anti-B. anthracis serum (PC1) or (C) naive horse serum (NC1) in PAD1-ELISA. Each dilution of serum sample was tested in technical triplicate. The twofold serum dilution starts with a dilution of 1:100, and PAD1 dilution starts with 1.6 μg/well. From the result, we determined the optimal concentrations of the antigen, antibody, and serum dilutions as follows: antigen, 0.4 μg/well; serum dilution, 1:100; second antibody dilution, 1:15,000.