Dose finding in the Ames Salmonella assay.

摘要: Threshold dose/concentration values, such as the lowest effective dose, minimum dose or concentration (LED, MED LEC, respectively) are in use an alternative to mutagen potency measures based on ‘rate’ measurements (e.g., slope of initial part dose‐response curve). In this respect, several statistical procedures for corresponding so-called ‘dose finding’ were proposed during last decades. However, most them disregard discrete nature responses plate colony count Ames Salmonellaassay. When counts agree with Poisson assumption, two considered here seem be appropriate finding. One is stepwise collapsing homogeneous control and counts; another consists constructing confidence limits mutation induction factor (MIF). non-overlapping, simple ‘visual’ non-parametric estimation LED possible. Applicability validity methods demonstrated data sets mutagenicity b-carboline alkaloid, harmine, one oxidation products apomorphine. © 2000 Elsevier Science B.V. All rights reserved.