Aflatoxin B; specific antibodies and their use in radioimmunoassay

New Zealand White rabbits immunized with covalent conjugates prepared from polylysine and the O-carboxy-methyloxime derivatives of either aflatoxin B1 (AFB1) or an analogue, 5,7-dimethoxycyclopentenon (2,3-c) coumarin, produced antibodies that bind 3H-AFB1. The specificities of the antisera with respect to aflatoxins BI, B2a, G1, G2, Q1, P1, and some other structually related compounds were determined. Radioimmunoassays that can detect levels as low as 0.27 pmoles (0.06 ng) of AFB1-were used to analyze serum, urine, and crude extracts of corn and peanut supplemented with aflatoxin. In the foodstuffs, as little as 1 mug AFB1/kg was measured. The immunoassay was at least as sensitive and specific as other available analytic methods, but did not require the purification of samples by chromatography before analysis. The technique may be particularly useful in epidemiologic studies designed to study the possible relationship between chronic aflatoxin ingestion and cancer.