Calcein AM (calcein acetoxymethyl ester) is a non-fluorescent reagent that easily permeates cellular membrane. Once it permeates live cells, esterases remove the acetomethoxy group allowing calcein to bind to calcium, which results in a strong green fluorescence. The increase of fluorescence is proportional to the number of live cells. Inside dead cells, the non-fluorescent calcein AM remains intact due to the lack of active esterases. The fluorescent signal from the conversion of calcein AM to calcein can be monitored at Ex/Em=494nm /520 nm.
The SensoLyte® Calcein Cell Viability Assay Kit provides a convenient tool to detect live cells. This kit can be used in proliferation, cytotoxicity, invasion, adhesion, migration and other cell-based assays.