Preparation and Evaluation of 125I-Aflatoxin B1

Aflatoxin B₁ (AfB₁), present in fungus infested crops is highly carcinogenic and is measured by immunoassays. ¹²⁵I labeled aflatoxin B₁ is a key reagent for development of radioimmunoassay (RIA) which exhibits less interference and better sensitivity than other immunoassays. Since AfB₁ lacks suitable functional groups for radiolabeling, an oxime derivative of AfB₁ was synthesised and evaluated by UV-spectrophotometry and ¹H NMR spectroscopy. ¹²⁵I-histamine was conjugated to AfB₁ oxime by mixed anhydride method and purified by solvent extraction followed by TLC. The tracer obtained was immunoreactive, stable as ethanolic solution and could be used in RIA.