Notes: Detection of the egg yolk protein vitellogenin (Vtg), egg shell proteins Zona radiata proteins (Zrp), cytochrome P450 1A (CYP1A) and Metallothionein (MT) are simple and sensitive biomarkers for endocrine pollutant exposure in fish. The Enzyme-Linked Immunosorbent Assay (ELISA) method is a well established method suitable for detection of such biomarkers. The semi-quantitative Biomarker ELISA Kit is well suited for applications such as environmental and effluent monitoring and can easily be combined with standard fish tests according to OECD Guidelines for Testing of Chemicals.