Calcein AM is a cell-permeant dye that can be used to determine cell viability. The acetomethoxy derivate of calcein (calcein AM) is used in biology as it can be transported through the cellular membrane into live cells, which makes it useful for testing of cell viability and for short-term labeling of cells. An acetomethoxy group obscures the part of the molecule that chelates Ca2+, Mg2+, Zn2+ and other ions. After transport into the cells, intracellular esterases remove the acetomethoxy group, the molecule gets trapped inside and gives out strong green fluorescence. As dead cells lack active esterases, only live cells are labeled and counted by flow cytometry.
We also offer it as 1 mg size (#7077), in DMSO (#7089, SP-Sol) and Extra Pure (#7025, X-Pure)