Comparison of enzyme-linked immunosorbent and indirect hemagglutination assays for determining anthrax antibodies.

An enzyme-linked immunosorbent assay has been established to measure anthrax antibody titers. The protective antigen component of anthrax toxin was used as the capture antigen. Two types of conjugates (protein A-horseradish peroxidase and anti-human immunoglobulin G plus immunoglobulin A plus immunoglobulin M-horseradish peroxidase) were tested. Results from enzyme-linked immunosorbent assay testing were compared with those from indirect hemagglutination titers on serum from vaccinees. The overall trend of enzyme-linked immunosorbent assay and indirect hemagglutination titers was significant. The enzyme-linked immunosorbent assay offered speed, precision, and reduced cost per test.