| Aflatoxin B1 widespreadly contaminates foods prepared by animals, as well as plants, and once ingested by animals, it will convert to some other toxic derivants, such as aflatoxin M1. Aflatoxin B1 is cancerigenic, teratogenic and mutagenic, which is great threat to humans'health. So it is very important for ensuring food safety to inhance the detection of AFB1.There are several methods to detect the content of AFB1, including Thin Layer Chromatography, High Performance Liquid Chromatography and immunological method. Thin Layer Chromatography is insensitive, inspecific, time-consuming, and easily interfered by fluorescent material. High Performance Liquid Chromatography is sensitive and accurate, howerever, the equipment is very expensive and the pre-processing is complicated. Compared with the two methods introduced before, Enzyme-linked immunosorbent assay (ELISA) can be used to screen a large number of samples, meanwhile, it is a sensitive, special and rapid method.Corn is frequently made into animal feeds in our country, mould development of corn often leads to active chronic toxicosis. To establish the ELISA method for detecting AFB1, this research synthesized complete antigen, developed high-grade antibodies using the technology of monoclonal antibody. AFB1 standard was added to corn samples, the process of extraction and purification was optimized, and finally a stable and reliable method to detect AFB1 in corn was established.O-(Carboxymethyl) hydroxylamine hemihydrochloride and AFB1 in pyridine reacted and generated AFB1 oximation, then the latter conjugated with protein forming complete antigen. In the course of reaction, TLC method was used to monitor the convertion of AFB1 in real time, UV scanning methd to identify the effect of synthesis, and the ratio of AFB1 to protein was calculated on the basis of the result of UV scanning. After the process of composition improved, the oximation ratio of AFB1 and the utilization rate of AFB1O increased a lot, and reached 84.3% and 55.4% respectively.AFB1-HSA was used to immunize Balb/C mouse, the titer of blood serum collected after the forth immunization reached 1:100,000. After screening, eight hybridoma cells in all which could persistenly excret antibodies against AFB1,were achieved and named with 1-5G4, 2-6A8, 2-A5, 2-B1, 2-B3, 2-B5, 2-B6 and 2-D3. Stability experiment indicated that, the titer of cultivation supernatant retained after culturing in vitro for thirty generations and anabiosised from liquid nitrogen.Five kinds of abdominal dropsy were made by injecting 1-5G4,2-6A8,2-A5,2-B6 and 2-D3 tumor cells to abdominal cavity of mice, and their titers were all above 1:1,000,000. 1-5G4 and 2-6A8 antibodies were used to establish ELISA method. Suitable concentration of the coated antigen and ascites titer were determined by chessboard test. The ascites titer and coated antigen reached 1:100,000 and 1:2,000 respectively. Calibration graphs were prepared. The limit of detection of this assay was established to be 0.1ng/ml,and the correlation value is high. The ELISA method can be used in practical detection.To cut down the interference of extract and raise extraction rate, the method of extracting AFB1 from corn was optimized. Intervention disappeared when the extrace were diluted four times. The recovery ratio were between 83.7%～127% when adding 1,5,20,and 100ng/ml AFB1 to corn,the reproducibility was fine.
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