Improvement of the long-term stability for dioxin toxicity evaluation method by enzyme-linked immunosorbent assay.

A dioxin enzyme immunoassay (EIA) is one of the methods that may satisfy the requirements to reduce the cost and turn around time for the dioxin analysis. We developed a dioxin enzyme-linked immunosorbent assay (ELISA) to rapidly analyze for trace levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in human milk. In this study, to aim to supply the stable assay quality, the development of long-term stable coated plates for the ELISA system was reported. To the conventional coated plate (wet plate), the dry plate ELISA indicated the stability to be able to store for 1.5 years at 11°C. The IC50 of this ELISA was 17 ± 4 pg/well. The standard curve showed almost the same as that of the wet plate. A fairly good correlation between cross-reactivity of the ELISA and WHO-TEF was achieved for environmental matrices. This ELISA should be more practical for environmental sample monitoring.