Bioassays are biological measurement methods that directly determine the effect of substances on living cells, tissues, or organisms. Het Waterlaboratorium (HWL) currently only uses in vitro bioassays with cells and bacteria, and exclude in vivo assays with living organisms.
Bioassays can be used to conduct sensitive research on the presence of chemicals with specific biological effects in water. This is also possible for water samples with complex mixtures of (unknown) substances, which are difficult to identify with a chemical approach. There are many biological processes in the cells of humans and animals that can be disrupted by chemicals. Therefore, the water sector has made a selection of processes (toxicological endpoints) that are most important to investigate in order to protect the health of drinking water consumers or aquatic life. Het Waterlaboratorium has in-house bioassays for all these processes. These are depicted in the figure below: