The Use of Cause-and-Effect Analysis to Design a High Quality Nano-Cyto-Toxicology Assay
Matthias Rosslein, John T. Elliott, Marc L. Salit, Elijah J. Petersen, Cordula Hirsch, Harald Krug, Peter Wick
An important consideration in developing standards and regulations that govern the production and use of commercial nanoscale materials is the development of robust and reliable measurements to assess potential biological effects of these nanomaterials products. These measurements typically require cell-based and other biological assays that provide an assessment of the risks associated with the nanomaterial of interest. In this report, we describe the use of cause-and-effect (C&E) analysis to design robust, high quality cell-based assays to test nanoparticle related-cytotoxicity. C&E analysis of the assay system identifies the sources of variability that influence the test result. These factors can then be used to design control experiments aid in establishing the validity of a test result. We demonstrate the application of C&E analysis to the commonly used 3- (4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell- viability assay. A novel 96-well plate design is proposed which incorporates a range of control experiments to assess multiple factors such as nanomaterial interference, pipetting accuracy, cell seeding density and the impact of a reference chemical toxicant. While this plate design was formulated specifically for the MTS assay, it is applicable to other cytotoxicity, ecotoxicity (i.e., bacteria toxicity), and nanotoxicity assays after assay-specific modifications.