Fluo 3 is a long wavelength calcium probe
that is practically nonfluorescent in its free ligand form, but its
fluorescence increases 60-80 times when it forms complexes with calcium.
Thus, it has been widely used with confocal laser fluorescent
microscopy because the microscope has an argon laser. The long
wavelength of the fluorescent signal is also convenient for minimizing
photodamage to sample cells. Fluo 3 is also useful for caged calcium and
others that are cleaved by the photoirradiation in the UV region. Fluo
3-AM is an acetoxymethyl ester derivative of Fluo 3 that can be easily
loaded into cells by incubation.
Hydrolysis of AM ester