A non-toxic enzyme-linked immunosorbent assay for aflatoxin B₁ using anti-idiotypic antibodies as substitutes

Immunoassays are widely employed techniques to detect aflatoxins since they are rapid, selective and sensitive. One common disadvantage of them is using aflatoxins as standard substances, which may trigger exposure risks to operators and environmental contamination without proper handling. Anti-idiotypic antibodies (anti-Ids or Ab2s), also named as internal-image anti-Ids, are able to mimic and function as antigens, so a non-toxic enzyme-linked immunosorbent assay (ELISA) for aflatoxin B₁ (AFB₁ ) is developed and validated using anti-Ids as substitutes.

Mouse monoclonal anti-idiotypic antibody (McAb2) to AFB₁ was generated by the hybridoma technique using Fab fragments of rabbit anti-AFB₁ idiotype antibody (Ab1) as immunogen. As indicated by indirect competitive ELISA, McAb2, represented an internal-image of antigen AFB₁ , was able to bind Fab with competition to AFB₁ . Then, analysis of AFB₁ in spiked samples by non-toxic ELISA using anti-Ids as substitutes was developed, and it showed no significant differences with comparison to AFB₁ as competitive antigens.

Our work demonstrated that anti-Ids could be used as internal-image mimicry of AFB₁ , and it had potential applications in immunoassays for antigen substitution to reduce operational risk for operators and environmental contamination. © 2016 Society of Chemical Industry.