Qualitative and quantitative detection of aflatoxin B-1 in poultry sera by enzyme-linked immunosorbent assay

An indirect competitive inhibition type enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of aflatoxin B-1 in poultry sera. Preincubation of aflatoxin B-1 samples with the antibody prior to competition yielded better results in terms of higher sensitivity. After competition, amount of antibody bound to solid phase was measured by incubation with anti-rabbit immunoglobulins coupled with horse raddish peroxidase, Intensity of colour decreased as the amount of free aflatoxin B-1 increased. Final detection of aflatoxin B-1 was made by (i) visual comparison with standard aflatoxin B-1, using dot-ELISA (qualitative) and (ii) by plate-ELISA, where optical density was measured at 492 nm (quantitative). Plate-ELISA was more sensitive than dot-ELISA, with sensitivity limits being 100 fg and 1 pg per 10 mu l, respectively. However, due to ease and speed of performance, dot-ELISA has greater potential as a test for the diagnosis of mycotoxicosis at the field level.