Calcein-AM

Synthetic. Chemical. CAS: 148504-34-1. Formula: C46H46N2O23. MW: 994.86. Synthetic. Calcein-AM is a non-fluorescent cell permeable and hydrophobic probe that, upon entering live cells, is cleaved by intracellular esterases, releasing the membrane-impermeable, hydrophilic, and intensely bright green fluorescent calcein. Better retained by viable cells than fluorescein, carboxyfluorescein, or BCECF, due to its low cytotoxicity. It can be used as an indicator of cell viability (dead cells lack cytoplasmic esterases), cell-cell communication, cytotoxicity or changes in intracellular calcium, fluoride, iron or mercury. Calcein-AM is a neutral substrate for multidrug resistance-associated protein 1 (MRP1) and multidrug resistance protein 3 (MDR3, P-glycoprotein 3) and has been used in flow cytometry studies to analyze the function of P-gp and MRP. Used as a cytosolic fluorophore in mitochondrial permeability studies to image pore transition. Viability assays using calcein are reliable and correlate well with the standard 51Cr-release assay. Spectral Data: lambdaex 496nm, lambdaem 516nm in 0.1M Tris pH 8.0.