Abstract: The toxicity data of 256 chemicals tested in both the 96-h Pimephales promelas mortality assay and the 2-d Tetrahymena pyriformis growth inhibition assay were evaluated using quantitative structure-activity relationships (QSARs). Each chemical was a priori assigned a mode of action of either narcoses or soft electrophilicity. Narcoses were separated into ...

Abstract: The acute toxicity of aliphatic and aromatic mono and diesters in two eucaryotic organisms was compared. The test systems were the static 2-d Tetrahymena pyriformis 50% population growth impairment (IGC50(-1)) assay, and the flow-through 4-d Pimephales promelas 50% mortality (LC50(-1)) assay. In ciliates, esters act via the nonpolar narcosis mechanism of toxic ...

Abstract: A short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) is reported. The 50% impairment growth concentration (IGC 50) is the endpoint of choice. Cultures are reared in 50 mL of a semi defined medium in 250-mL Erlenmeyer flasks. Definitive test replicates consist of a minimum of 5 different concentrations of each ...