Fluo-3 is a fluorescence indicator of intracellular calcium (Ca2+). It is used to measure Ca2+ inside living cells in flow cytometry and confocal laser scanning microscopy using visible light excitation (compatible with argon laser sources operating at 488nm). Fluo-3 is an essentially nonfluorescent compound, but upon binding of Ca2+ its fluorescence increases sharply with an emission maximum at 525nm suitable for conventionally used detectors designed for fluorescein isothiocyanate (FITC) measurements. This large change in fluorescence coupled with a good yield of photons provides very high contrast which allowed the detection of microscopic Ca2+ release events inside cells called \"Calcium sparks\". Whereas the salts of fluo-3 are unable to penetrate cells, loading can be achieved using its acetoxymethyl (AM) ester derivative. Once inside the cell, unspecific esterases cleave the ester effectively trapping fluo-3.

CAS：123632-39-3
中文别名：
英文别名：FLUO 3;
分子式：C36H30Cl2N2O13
分子量：769.535
精确质量：768.112
Psa：224.58
Logp：5.2946

密度：1.66 g/cm3
沸点：1056ºC at 760 mmHg
闪点：592.4ºC
储存条件：-20ºC