Computer software for the management of Salmonella mutagenicity assay data has been developed based on the recommendations of genetic toxicologists and statisticians. The panels of international experts convened to design the software package included representatives of the Federal government, industry, academia, and research institutions. The resulting microcomputer program automatically supplies an accepted method of statistical analysis, and will, at the user's option, supply statistics from several different models. A potentially major source of variability among investigators is largely eliminated. Statistics supplied include: (1) the initial slope of the dose-response curve (potency estimate), (2) a determination as to whether the computed slope is statistically different than zero and (3) an indication of whether each dose is significantly different than the background (t-Test). Slope estimation is performed using either a linear or one of two non-linear models. A standardized data output format is provided to facilitate review of results.