Activation of the receptor initiates a cascade of events leading to the expression of the reporter gene product (e.g. β-galctosidase) which converts a substrate (e.g. CPRG) which leads to a measurable color change from yellow to red in the medium.
Total assay time is usually 2–3 days, but faster protocols (18 hrs.
[4] Several yeast cell lines have been developed for the YES and YAS assay, both proprietary and publicly available.
[5] Substances with an activating or inhibitory effect on the estrogen and/or androgen receptor of organisms may interfere with reproduction, affect the metabolism and immune system and induce the formation of tumors.
[6] This assay is suitable for detecting numerous natural and synthetic hormonally active substances such as environmental toxins from everyday products, e.g. birth control pill ingredients (17α-ethinylestradiol), synthetic materials (bisphenol A, phthalates), pesticides (methoxychlorine) and non-ionic surfactants (alkylphenols).