A RAPID AND SENSITIVE CELL-CULTURE BIOASSAY FOR MEASURING ETHOXYRESORUFIN-O-DEETHYLASE (EROD) ACTIVITY IN CULTURED-HEPATOCYTES EXPOSED TO HALOGENATED AROMATIC-HYDROCARBONS EXTRACTED FROM WILD BIRD EGGS

An improved method for determining the effect of polychlorinated biphe nyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and other halog enated aromatic hydrocarbons (HAHs) on ethoxyresorufin-O-deethylase (E ROD) activity in primary cultures of chicken embryo hepatocytes is des cribed. Cells were cultured in 48-well plates, and EROD activity was d etermined with a computer-operated fluorescence multi-well plate reade r. Assays were carried out directly within multi-well plates, and dose -response curves were obtained approximately 100 times faster than oth er methods. The method can be used to measure EROD-inducing potencies of complex mixtures of HAHs extracted from wild bird eggs. It may have potential use as a cost-effective screening tool for determining the toxic potencies of complex mixtures of HAHs in environmental samples.