Efficient methods for conjugation of mycotoxins to proteins have been developed in the early phase of this study. Specific antibodies against different mycotoxins including aflatoxins B?1?, B?2a?, B1-diol, G?1?, M?1?, Q?1?, ochratoxin A, sterigmatocystin, and trichothecene mycotoxins such as T-2 toxin, diacetoxyscirpenol, deoxynivalenol and deoxyverrucarol have been obtained in our laboratory in the past few years. Antibodies obtained from rabbits after immunizing conjugates that were prepared by linking different side chains in the aflatoxin and trichothecene molecules to protein showed a diversified specificity. Antibodies against aflatoxins B?2a? and B1-diol were also found to be reactive with aflatoxin-DNA adduct. With the availability of these antibodies, simple and rapid, i.e., no cleanup treatment of samples to be assayed, radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) for the determination of these mycotoxins in grains and biological fluids have been developed. The sensitivity of RIA was generally in the range of 0.25 to 0.5 ng per assay. ELISA was found to be more sensitive than RIA, with a detection limit in the range of 2.5 to 25 pg per assay. Pretreatment of milk and human urine samples with a Sep-Pak, C-18 reversed-phase cartridge permits detection by direct ELISA of 10 to 25 ppt of aflatoxin M?1? in the sample. This technique was found to be very useful for monitoring aflatoxin M?1? in human urine samples obtained from the subjects who had consumed aflatoxin B?1?. A direct correlation between the dietary level of aflatoxin B?1? and aflatoxin M?1? excreted in human urine in a selected high incidence liver cancer region has been observed. In addition, immunohistochemical techniques for monitoring the aflatoxin, ochratoxin, and T-2 toxin in the tissues of mice and rats that have ingested these mycotoxins have been developed. (HI)
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