Qualification and performance characteristics of a quantitative enzyme-linked immunosorbent assay for human lgG antibodies to anthrax lethal factor antigen.

The contribution of Bacillus anthracis lethal factor (LF)-specific immune responses to protection against anthrax disease in humans remains incompletely defined due, in part, to a paucity of qualified reagents and a lack of standardized serological assays. Toward this end, we have identified and characterized suitable positive quality control and standard reference sera and developed, optimized, and qualified an enzyme-linked immunosorbent assay (ELISA) to measure LF-binding IgG. Herein we describe the performance characteristics of this ELISA and propose criteria for its use in the detection and quantification of anti-LF IgG in human serum.