Learn about developing a testing strategy for EDCs in water (and how INDIGO can help)
INDIGO Biosciences cell-based reporter assays have been used in environmental research on water for years due to their ease of use. Our CSO Jack Vanden Heuvel has even done his own research in this field utilizing INDIGO kits. (Take a look at the posters “Environmental and human health impacts of spreading oil and gas wastewater on roads” and “Detection and removal of biologically active organic micropollutants from hospital wastewater.”) Using in vitro receptor transactivation assays like those produced by INDIGO Biosciences is a crucial step to improve monitoring of our water systems and decrease the risk posed by complex mixtures of chemicals in the environment. Reporter assays can detect the cumulative toxicity posed by mixtures of known and unknown chemicals found in a sample. Cell-based nuclear receptor specific reporter assays such as INDIGO’s estrogen receptor assays, androgen receptor assays, and thyroid receptor assays can screen for endocrine-like activity in water samples that can cause adverse health effects to humans and the environment.
Though there is testing and regulation to identify single compound concentrations, there is not a universally accepted method for utilizing bioassays that more accurately reflect exposure for regulating the levels of EDC (Endocrine Disrupting chemicals) in water resources. Many authorities around the world are evaluating several methods to better assess and regulate the level of various pollutants that activate the EATS (Estrogen, Androgen, Thyroid, and Steroidogenesis) pathways.
Developing a Strategy to Test for EDCs Utilizing Bioassays
In an effort to help those looking into utilizing bioassays to develop a testing strategy for EDCs, a paper was published in the Journal of Environmental Research titled “Towards regulation of Endocrine Disrupting chemicals (EDCs) in water resources using bioassays – A guide to developing a testing strategy.” It is authored by experts in the field of environmental monitoring. In this paper the researchers outline various in vitro and in vivo bioassays for EDC screening, different preparations of water samples for bioassays, and recommendations for those looking to develop an EDC testing strategy.
Of the diverse types of in vitro and in vivo assays, the researchers who authored the paper recommend the use of cell-based assays as the first step in testing because in vitro bioassays provide cost effective methods to test cumulative mixtures, reduce the use of animals in testing, and generate data that can be integrated into adverse outcome pathways for better risk evaluation.
In developing a strategy to test for EDCs utilizing in vitro bioassays they recommend:
- First selecting in vitro bioassays for multiple endpoints of the EATS (Estrogen, Androgen, Thyroid, and Steroidogenesis) pathways, and if possible, include non-EATS pathways
- Conduct two cytotoxicity assays – assessing two different pathways/mechanisms of cell death
- Third they recommend including receptors from various animal species if possible
- Fourth prioritize internationally standardized and/or commercial assays that come with quality control
- And finally define effect-based trigger values for each bioassay, which will act as a threshold for risk assessment.
In the paper they note that when evaluating various receptor transactivation assays to use, the reproducibility and sensitivity of the bioassay is a crucial factor. The choice of species for the receptor is also important as it can modulate the sensitivity of the receptor transactivation assay. Another thing they mention to be aware of is while you might be considering using YES/YAS assays, the use of yeast cells is no longer recommended by both the OECD (2018) and the US-EPA (EDSTAC, 1998).
Don’t Know What Your Next Step Should Be?
Wherever you are in developing a strategy to test for EDCs, INDIGO can help. INDIGO has many years of experience with developing and producing commercial luciferase reporter assays kits for EATS and non-EATS pathway receptors for researchers all over the globe. INDIGO has the world's largest selection of all-inclusive luciferase reporter transactivation assays for nuclear receptors, as well as other receptors. Our kits contain along with the already transfected reporter cells, all the reagents you will need to perform the assay, as well as a cell culture ready assay plate so you will have no issues waiting on backordered reagents or other components necessary to perform the assay. We perform quality control and quality assurance testing on each lot to ensure that every assay kit we produce is sensitive and robust.
INDIGO also has a range of ortholog receptors from various animal species including dog, mouse, rat, zebrafish, and monkey, to include in your testing strategy. This way you can choose the most pertinent receptor for your strategy. INDIGO also has a live cell multiply assay to determine if samples exert cytostatic, cytotoxic, or cytolytic activities to validate the data.
INDIGO has everything you need to develop a robust testing strategy using cell-based bioassays for evaluating EDCs in water including knowledgeable experts. We provide ready to use kits or can perform service studies if you do not have the facilities to execute the strategy yourself including Solid Phase Extraction. Learn more about INDIGO’s Environmental Testing Solutions.
Want to Learn More About Endocrine Disruption?
For a more in-depth review of EDCs and their mechanism of action, in particular focusing on their interaction of nuclear receptors, take a look at this scientific whitepaper by Jack Vanden Heuvel, PhD Nuclear Receptors & Endocrine / Metabolic Disruption.