Biological effects of contaminants: Microplate method for measurment of ethoxyresorufin-O-deethylase (EROD) in fish

Interest in the use of mixed function oxidase (MFO) as a monitoring tool for measuring the effects of pollntants derives from basic research carried out over the past twenty years. 

The MFO system catalyses the degradation of both endogenous and exogenous lipophilic substrates to polar water-soluble products which are more easily excreted. It is present at relatively low activity in wild fish and its activity increases dramatically, apparently to enhance the degradation and clearance of offending compounds. This suggests that the activity of the MFO system in naturally contaminated organisms might be a measure ofthe degree of chemical contamination. There have been a number of field studies in which elevated MFO activity in fish was found to be associated with contamination by hydrocarbons.

The method described here has been adapted from the techniques described by Burke and Mayer (1974) and Klotz and Stegeman (Klotz et al., 1985) for routine measurements of ERaD in flatfish. The method uses microplate technology and is suitable for use in the field on research vessels and in the laboratory.