A biosensor that monitors cell morphology with electrical fields

Describes a "whole cell" biosensor that is very useful in the field of animal cell tissue culture and in many ways is akin to the canary in a coal mine. The heart of this method, called ECIS for electric cell-substrate impedance sensing, is a small gold electrode immersed in tissue culture medium. When cells attach and spread on this electrode, the measured electrical impedance changes because the cells constrain the current flow. This changing impedance can be interpreted to reveal useful information about cell behaviors. Since these behaviors, such as spreading and locomotion, involve the coordination of many biochemical reactions, they are extremely sensitive to most external parameters such as temperature, pH, and a myriad of chemical compounds. This broad response to changes in the environment allows this method to serve as a general biosensor. The measurements are easily automated, and the general conditions of the cells can be monitored by a personal computer controlling the necessary instrumentation.<<ETX>>