Selection of the separation step in the radioimmunoassay for aflatoxin B1 using125I as a marker

Abstract

Aflatoxin B1 was assayed by radioimmunoassay (RIA) using125I-labelled antigen. The immunoreactivity of the radioligand applied is very close to the immunoreactivity of free aflatoxin B1. The logit-log analysis was used to select the best separation of free and bound radioligand. The adsorption of the free radioligand on dextran-coated charcoal was found to be superior from the viewpoint of the assay sensitivity and accuracy. The detection limit of aflatoxin B1 was about 10 pg per tube. The assay accuracy was estimated to 3.3% in intraassay and to 7.0% in interassay.