Cell Meter? Cell Viability Assay Kit *Green Fluorescence*. Our Cell Meter? assay kits are a set of tools for monitoring cell viability. There are a variety of parameters that can be used for monitoring cell viability. This kit uses the non-fluorescent calcein AM that becomes strongly fluorescent upon entering into live cells. Calcein AM is a hydrophobic compound that easily permeates intact live cells. The hydrolysis of the non-fluorescent calcein AM by intracellular esterases generates the strongly fluorescent hydrophilic calcein that is well-retained in the cell cytoplasm. The esterase activity is proportional to the number of viable cells, and thus directly related to the fluorescence intensity of calcein generated from the esterase-catalyzed hydrolysis of calcein AM. Cells grown in black-walled plates can be stained and quantified in less than two hours. The assay is more robust than the tetrazolium salt or Alarmar Blue?-based assays. It can be readily adapted for high-throughput assays in a wide variety of fluorescence platforms such as microplate assays, immunocytochemistry and flow cytometry. It is useful for a variety of studies, including cell adhesion, chemotaxis, multidrug resistance, cell viability, apoptosis and cytotoxicity. The kit provides all the essential components with an optimized cell-labeling protocol. It is suitable for proliferating and non-proliferating cells, and can be used for both suspension and adherent cells. Using 100 ul of reagents per well in a 96-well format, this kit provides sufficient reagents to perform 500 assays. Using 25 ul of reagents per well in a 384-well format, this kit provides sufficient reagents to perform 2000 assays.