Cells as Sensors. Effect-Directed Rather than Concentration Analysis

Cells are the fundamental base units of life and can be used as living sensors, if the reaction of the cells to an external chemical, biological or even physical stimulus can be sensitively detected and converted into an electrical signal. Physical signal transducers such as transistors, electrodes or optrodes are particularly suitable for this, because they allow cells to be examined non-invasively and without labeling, even over long observation periods. The quantification of biological effects is thus made possible through such biotechnological hybrids of living cells and technical components, without having to rely on the use of experimental animals. This article provides an overview of the possibilities for culturing animal cells in a laboratory environment, describes the state of the art with regard to signal transducers being used for analysis and concludes with selected examples of the use of cellular sensors in drug testing and risk assessment.