Enzyme immunoassay for the rapid quantitative determination of Aflatoxin B1 in cereals and beer/gyle.
Background: Aflatoxins belong to the class of mycotoxins. Chemically they are defined as difuranocyclopentanocumarines or difuranopentanolidocumarines, i.e. aflatoxins contain a dihydrofuran or a tetrahydrofuran ring, to which a substituted cumarin system is condensed. Out of about 20 known aflatoxins, the moulds Aspergillus flavus and A. parasiticus produce exclusively aflatoxin B1, B2, G1 and G2, and all the other aflatoxins are derivates of these four. The derivates are developed either by metabolism in humans, animals and microorganisms or by environmental reactions.
In the European Union the limits for aflatoxin B1 are 2 – 12 ppb for regular food products. Thus a monitoring of food and feed with respect to the concentration of aflatoxin B1 is obligatory. Aflatoxin B1 ELISA represents a highly sensitive detection system and is particularly capable of the rapid quantification of aflatoxin B1 contaminations in cereals and beer.
Description: The Aflatoxin B1 quantitative test is based on the principle of the enzyme-linked immunosorbent assay. An antibody binding protein is coated on the surface of a microtiter plate. Aflatoxin B1 containing samples or standards, an aflatoxin-peroxidase conjugate and an antibody directed against aflatoxins are given into the wells of the microtiter plate. The conjugate competes with the aflatoxin B1 of samples/standards for the limited number of antibody sites. Simultaneously the anti-aflatoxin antibody is bound to the antibody-binding protein coated on the microtiter plate. After 10 minutes incubation at room temperature the wells are washed with diluted washing solution to remove unbound material. A substrate solution is added and incubated for 10 minutes, resulting in the development of a blue colour. The colour development is inhibited by the addition of a stop solution, and the colour turns yellow. The yellow colour is measured photometrically at 450 nm. The concentration of aflatoxin B1 is indirectly proportional to the colour intensity of the test sample.
- The kit contains reagents for 96 determinations;
- Microtiter plate consisting of 12 strips with 8 breakable wells;
- Aflatoxin B1 Standards: 0, 1.5, 3, 6, 12, 24 ppb;
- ELISA reader at 450 nm;
- Standard range: 1.5 - 24 ppb;
- Sensitivity analytical: 0.5 ppb.