Collaborative Study of the Chicken Embryo Bioassay for Aflatoxin B1

Abstract A collaborative study of the bioassay for the detection of aflatoxin B1, 26.057–26.061, was undertaken with 9 laboratories participating. The study was designed to evaluate the toxicity of an aflatoxin B1 standard, and an unknown quantity of aflatoxin B1 extracted from peanut butter. The baseline was provided by an assay of an extract of an aflatoxin-free peanut butter and by the appropriate solvent and untreated control eggs. The data were analyzed for linearity of response and agreement of the LD-50’s and slopes. In general, a linear dose-response relationship was exhibited, and there was good agreement of the slopes and LD-50’s and their associated standard errors. The method has been adopted as official first action.