Immunofiltration assay for aflatoxin B1 based on the separation of pre-immune complexes.

A new approach for quantitative determination of AFB1 based on the separation of pre-immune complexes in the same immunoassay system has been developed. No additional step for the separation of pre-immune complexes is required. The method uses a test device for separation of pre-immune complexes from the free AFB1-enzyme conjugate by filtration through the membrane strips spotted with anti-AFB1 antibody. The bound enzyme conjugate was visualized by super-catalyzed reporter deposition (Super-CARD) signal amplification method. The measured signal intensity is directly proportional to the amount of AFB1 present in the sample. The detection limit obtained by the present method was 15 pg/ml. The data on the analytical parameters indicate that the new format of AFB1 detection in foodstuffs is reproducible, accurate and specific. The method is user friendly and does not require any costly equipment or a well-equipped laboratory.