Only few of the many chemical pollutants in water can be effectively measured by current analytical techniques. Especially hydrophilic compounds are hard to extract and unknown compounds (e.g., metabolites and reaction products) are hard to identify. Also, chemical techniques cannot provide information about the potential toxic effects of these compounds and mixtures thereof. Bioassays can quantify the toxic potency of bioactive pollutants, but most of the existing bioassays are either very specific for one or a few compounds or are non-specific indicators for general toxic effects. In this research, an invertebrate assay was successfully developed based on the genetic response of the nematode Caenorhabditis elegans to toxic compounds. The newly developed bioanalytical approach can simultaneously detect multiple mechanisms of toxicity in single test.