Development of a multiplex flow cytometric microsphere immunoassay for mycotoxins and evaluation of its application in feed

A multi-mycotoxin immunoassay—using the MultiAnalyte Profiling (xMAP) technology—is developed and evaluated. This technology combines a unique color-coded microsphere suspension array, with a dedicated flow cytometer. We aimed for the combined detection of aflatoxins, ochratoxin A, deoxynivalenol, fumonisins, zearalenone and T-2-toxin in an inhibition immunoassay format. Sets of six mycotoxin-protein conjugates and six specific monoclonal antibodies were selected, and we observed good sensitivities and no cross-interactions between the assays in buffer. However, detrimental effects of the feed extract on the sensitivities and in some cases on the slopes of the curves were observed and different sample materials showed different effects. Therefore, for quantitative analysis, this assay depends on calibration curves in blank matrix extracts or on the use of a suitable multi-mycotoxin cleanup. To test if the method was suitable for the qualitative detection at EU guidance levels, we fortified rapeseed meal, a feed ingredient, with the six mycotoxins, and all extracts showed inhibited responses in comparison with the non-fortified sample extract. Contaminated FAPAS reference feed samples assigned for a single mycotoxin showed strong inhibitions in the corresponding assays but also often in other assays of the multiplex. In most cases, the presence of these other mycotoxins was confirmed by instrumental analysis. The multiplex immunoassay can be easily extended with other mycotoxins of interest, but finding a suitable multi-mycotoxin cleanup will improve its applicability

De land- en tuinbouw op IJsselmonde

In dit rapport is een analyse gemaakt van de veranderingen in de agrarische struktuur gedurende de afgelopen jaren en wordt globaal aangegeven, welke veranderingen er in de komende jaren te verwachten zijn. Dit heeft betrekking op de belangrijkste elementen van de agrarische struktuur: het aantal bedrijven en arbeidskrachten, de oppervlakte kultuurgrond en het gebruik hiervan, de produktieomvang en -samenstelling. Alvorens in te gaan op de ontwikkelingen in de land- en tuinbouw worden enkele kenmerken naar voren gehaald van de omgeving, waarin de land- en tuinbouw hier funktioneert: de ontwikkeling van de bevolking en de ruimtelijke ordenin