We have been developing a new means to electrically study animal cells grown in tissue culture and intend to make a commercial device suitable for use in the medical/biological research and testing market. The instrumental method, referred to as ECIS (electric cell-substrate impedance sensor), is a non-invasive technique that measures several parameters related to cell behavior, some of which have previously been difficult to quantify. These include adhesion and spreading, cell growth, cell motility, and the barrier function of cell monolayers. The objective of the proposed research is to test the feasibility of using this approach to evaluate the cytotoxicity of compounds. The cell behaviors detected by ECIS are complex and, hence, require the integrated activities of many cellular systems. It is hoped their measurement will be particularly useful in screening potentially toxic compounds without the use of whole animals. Specifically, extensive ECIS measurements will be carried out using different cell lines exposed to varying concentrations of compounds with well documented cytotoxicity. These dose-response data will be statistically compared with existing data both from established cell culture assays and from whole animals. This aspect of the research will be carried out in collaboration with the Center for Alternatives to Animal Testing at Johns Hopkins University.