Application of immunoaffinity chromatography and enzyme immunoassay in rapid detection of aflatoxin B1 in chicken liver tissues

Department of Veterinary Pathology, Microbiology and Parasitology, University of Nairobi, P.O. Box 29053, Nairobi, Kenya. phealth@nbnet.co.ke

Existing physicochemical analytical methods for the determination of aflatoxins in animal tissues are expensive, cumbersome, and hazardous. To offer an alternative to these methods, a novel and highly sensitive immunochemical method for the rapid detection of aflatoxin B1 (AFB1) in chicken liver tissues is described in this study. Liver tissues were homogenized with cold methanol-acetone (50:50), followed by AFB1 extraction with methanol-acetone-PBS (25:25:50). The tissue extracts were, with or without further purification by immunoaffinity chromatography (IAC), applied to a highly sensitive direct ELISA for determination of AFB1. The detection limits for this assay were 15 +/- 0.77 pg/mL when standards and samples were dissolved in methanol-PBS (10:90) and 17 +/- 2.0 pg/mL when methanol-acetone-PBS (5:5:90) solution was used. The average recoveries of AFB1 were 54.3 to 65.5% in artificially contaminated tissue samples at 1 to 5 ng/g. In samples spiked with AFB1 at 1 ng/g, the method had diagnostic sensitivity and specificity of 100% for samples processed with IAC and 91.7 and 100%, respectively, for samples without IAC purification. The test was successfully applied to the detection of AFB1 in liver tissues from chickens that were experimentally dosed with AFB1. It is hoped that this test will be applicable in rapid detection of aflatoxins in poultry meats and in diagnosis of aflatoxicosis in chicken.