Abstract

In this chapter several fluorescent probes for the assessment of cell viability, types of cell death, identification of signals, cellular traffic and connections will be described. These biomedical fields have increasing interest [1-3]. The fluorescence histochemistry of enzymatic activity is currently applied in assays for cell viability, apoptotic processes, and detection of reactive oxygen species (ROS). Several probes of viability and signaling are also markers of oxidative stress and redox visualization. Numerous probes are now commercially available for studies on cell metabolism and toxicity, signal transduction, drug screening, molecular diagnosis, etc. Fluorescent labels and biosensors are applied to perform quali- and quantitative analysis of normal and pathological cell processes (i.e. sensing dyes for trans-membrane potential, ions, ROS, pH, etc). There exist also approaches to the direct real-time signal imaging of live-cells in vitro and in vivo, and for 2D and 3D analysis.