Development of a radioimmunoassay procedure for aflatoxin B1 measurement

A radioimmunoassaay (RIA) procedure to measure aflatoxin B-1 (AfB(1)) in agricultural commodities was developed. AfB(1) oxime derivative was synthesized, characterized, and used for preparation of I-125-labeled AfB(1). Antiaflatoxin B-1 serum was raised in-house using AfB(1)-bovine serum albumin conjugate as immunogen. The assay system was optimized in the range of 0.2-5 ng/mL, using a liquid phase (PEG) as well as a solid phase (coated polystyrene beads) separation system. Inter-assay and intra-assay variations, recovery, and parallelism studies validated the assay. AfB(1) analysis was carried out in nearly 130 samples of different agricultural commodities. The correlation coefficient was determined using commercial ELISA and in-house-developed RIA methods.