Calcein AM is a widely used green fluorescent cell marker. Calcein AM is membrane-permeant and thus can be introduced into cells via incubation. Once inside the cells, calcein AM is hydrolyzed by endogenous esterase into the highly negatively charged green fluorescent calcein, which is retained in the cytoplasm. Calcein AM is an excellent tool for the studies of cell membrane integrity and for cell tracing. Supplied in lyophilized form or as a solution in anhydrous DMSO at 4 mM (80011-1) or 1 mg/mL (1 mM) (80011-2). Calcein AM is also offered in our Cell Viability and Cytotoxicity Assay Kit.   &lamba;Ex/&lamba;Em (calcein) = 494/517 nm (pH 8)  Colorless solid soluble in DMSO  Store at -20°C and protect from light  C46H46N2O23  MW: 995