After developing  the A-YES®, a bioassay that uses Arxula adeninivorans as biosensor, we modified and improved the test system YES (Yeast Estrogen Screen, McDonnell et. al, 1991*) which is based on the estrogen sensitive yeast Saccharomyces cerevisiae. Henceforth users will be provided with a quick and easy ready-to-use test kit to analyze the estrogenic activity of aqueous solutions and extracts. A reduced analysis time (approximately 22 hours) and a extended shelf life due to freeze-dried biosensors and other test kit components are further advantages of the new S-YESMD. After factorial in house validation with different sample types the storage stability was tested under defined conditions. Currently we are testing if the new test system meets the ISO-Standard 19040-1.

*McDonnell, D.P., Nawaz, Z., Densmore, C., Weigel, N.L., Pham, T.A., Clark, J.H., O’Malley, B.W. 1991. High level expression of biologically active estrogen receptor in Saccharomyces cerevisiae. The Journal of steroid biochemistry and molecular biology 39(3): pp. 291-297