Test kits based on the ELISA principle are not necessarily only in the microtiter format,
thus requiring exact pipettes and photometric readers allowing quantitative determination.
They can also be supplied in qualitative formats such as small cups (e.g. Aflacup), where an
enzymatic color reaction visualizes within 5 min if aflatoxins are present or not at a certain
cut-off level. This refers in general to so-called flow-through assays, where mycotoxinantibodies
are coated to a membrane surface, which is soaked with the sample extract.
Mycotoxins and mycotoxin-conjugates compete for the limited antibody binding sites, so
that after washing and addition of a substrate solution a color reaction can be observed,
indicating whether higher or lower levels than the proposed cut-off level are present in the
sample.