Description
Fluo-Forte® Calcium Assay Kits detect mobilization of intracellular calcium utilizing a fluorogenic calcium-binding dye optimized for superior cell-permeability and retention. The self-quenching dye undergoes an electronic change upon binding of calcium, resulting in a several order of magnitude greater fluorescence.
Mechanism of Action
The fluorogenic calcium-binding dye is provided to the cells as an acetoxymethyl (AM) ester, which is cell-permeable. Once inside the cells, the dye is hydrolyzed by intracellular esterases, which leads to generation of a cell membrane impermeable negatively charged form. In the absence of calcium, the calcium-binding moiety portion of the probe quenches the fluorescence of the fluorophore portion of the probe by photo-induced electron transfer. Binding of calcium relieves quenching and results in a several order of magnitude increase in the fluorescence emission intensity, with no shift in wavelength. The dye is capable of binding to physiologically relevant levels of calcium and increases in intracellular calcium lead to an increased fluorescence signal, which is readily measurable