Calcein AM (Calcein acetoxymethyl ester), a non-fluorescent, cell permeable compound, has been known to convert to the strongly green fluorescent calcein when hydrolyzed by intracellular esterases in live cells. It is widely used for determining cell viability since the fluorescence intensity of calcein is proportional to the amount of live cells. Calcein is a photostable reagent and is well retained in the cytoplasm of live cells and is not influenced by intracellular pH. Its bright green fluorescence can be monitored at Ex/Em=494nm /520 nm.
Amongst dye reagents, including BCECF, AM and Carboxy-fluorescein diacetate, Calcein AM is the most suitable indicator for staining viable cells due to its low cytotoxicity property and does not affect cell proliferation or viability. Calcein AM is used in cell invasion, adhesion, migration and other cell-based assays.
*Information on Calcium AM supplied by AnaSpec